出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/09/04 09:08:26」(JST)
Contributors
| Ovarian cancer (human) | |
|---|---|
| Classification and external resources | |
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Micrograph of a mucinous ovarian carcinoma stained by H&E.
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| ICD-10 | C56 |
| ICD-9 | 183, 220 |
| ICD-O: | varied |
| DiseasesDB | 9418 |
| MedlinePlus | 000889 |
| eMedicine | med/1698 |
| NCI | Ovarian cancer |
| Patient UK | Ovarian cancer |
| MeSH | D010051 |
Ovarian cancer is when cancer forms from the ovary.[1] It is due to the development of abnormal cells that have the ability to invade or spread to other parts of the body.[2] Early on there is often no symptoms. Later symptoms may include: bloating, pelvic pain, and abdominal swelling among others.[3] Common areas of spread include the lining of the abdomen, lungs, liver or lymph nodes.[4]
Ovarian cancer occurs more frequently in women who ovulate more, thus those who never have children are at increased risk.[5] Other risk factors include hormone therapy after menopause, fertility medication, smoking and obesity.[1][6] Factors that decrease the risk include hormonal birth control, tubal ligation, and breast feeding.[6] About 10% of cases run in families and those with the gene mutations BRCA1 or BRCA2 have an approximately 50% risk of the disease. The most common type, making up more than 95% of cases, are ovarian carcinomas. They include five main subtypes of which high-grade serous is most common. These tumors are believed to usually start from the cells covering the ovaries,[5] though some may form from the fallopian tubes.[7] Less common types include germ cell tumors and sex cord stromal tumors.[5] The diagnosis is confirmed by examination of a biopsy usually removed during surgery.[3]
Screening is not recommended in women who are at average risk as evidence does not support a reduction in death and there is a high rate of false positive tests leading to unneeded surgery.[8] Those at very high risk may have their ovaries removed as a preventative measure.[1] If treated early ovarian cancer may be curable. Treatments often include some combination of surgery, radiation therapy or chemotherapy.[3] Outcomes depends on the extent of the disease and the sub-type of cancer present.[5] The overall five year survival rate in the United States is 45%.[9] Outcomes are worse in the developing world.[5]
In 2012 ovarian cancer occurred in 239,000 women and resulted in 152,000 deaths. This made it the seventh most common cancer and the eighth most common cause of death from cancer in women. It is more common in North America and Europe than Africa and Asia.[5]
Signs and symptoms of ovarian cancer are frequently absent in early stages and when they exist they may be subtle.[10] In most cases, the symptoms persist for several months before being recognized and diagnosed. Most typical symptoms include: bloating, abdominal or pelvic pain, difficulty eating, and possibly urinary symptoms.[11] If these symptoms start to occur more than 12 times per month, after no history of such symptoms, the diagnosis should be considered.[11]
Other findings include an abdominal mass, back pain, constipation, tiredness and a range of other non-specific symptoms, as well as more specific symptoms such as abnormal vaginal bleeding or involuntary weight loss.[12] There may be a build-up of fluid (ascites) in the abdominal cavity.
Ovarian cancer is associated with increased age, family history of ovarian cancer (9.8-fold higher risk), anaemia (2.3-fold higher), abdominal pain (sevenfold higher), abdominal distension (23-fold higher), rectal bleeding (twofold higher), postmenopausal bleeding (6.6-fold higher), appetite loss (5.2-fold higher), and weight loss (twofold higher).[13]
In most cases, the exact cause of ovarian cancer remains unknown. The risk of developing ovarian cancer appears to be affected by several factors:[14]
Combined oral contraceptive pills are a protective factor.[17][18] Later age at menarche, early age at first pregnancy, and older age of final pregnancy have also been shown to have a protective effect.[citation needed] The risk is also lower in women who have had their fallopian tubes blocked surgically (tubal ligation).[17][18] Tentative evidence suggests that breastfeeding lowers the risk of developing ovarian cancer.[19]
The relationship between use of oral contraceptives and reduced risk of ovarian cancer was shown in a summary of results of 45 case-control and prospective studies. Cumulatively these studies show a protective effect for ovarian cancers. Women who used oral contraceptives for 10 years had about a 60% reduction in risk of ovarian cancer (risk ratio .42 with statistical significant confidence intervals given the large study size, not unexpected). This means that if 250 women took oral contraceptives for 10 years, 1 ovarian cancer would be prevented. This is by far the largest epidemiological study to date on this subject (45 studies, over 20,000 women with ovarian cancer and about 80,000 controls).[20]
The ovaries contain eggs and secrete hormones that control the reproductive cycle. Removing the ovaries and the fallopian tubes greatly reduces the amount of the hormones estrogen and progesterone circulating in the body. This can halt or slow breast and ovarian cancers that need these hormones to grow.[21]
The link to the use of fertility medication, such as Clomiphene citrate, has been controversial. An analysis in 1991 raised the possibility that use of drugs may increase the risk of ovarian cancer. Several cohort studies and case-control studies have been conducted since then without demonstrating conclusive evidence for such a link.[22] It will remain a complex topic to study as the infertile population differs in parity from the "normal" population.
There is good evidence that in some women genetic factors are important. Carriers of certain BRCA mutations are notably at risk. The BRCA1 and BRCA2 genes account for 5%–13% of ovarian cancers[23] and certain populations (e.g. Ashkenazi Jewish women) are at a higher risk of both breast cancer and ovarian cancer, often at an earlier age than the general population.[24] Patients with a personal history of breast cancer or a family history of breast and/or ovarian cancer, especially if diagnosed at a young age, may have an elevated risk, and should be tested for any genetic risk.
In the United States, 5 of 100 women with a first-degree relative with ovarian cancer will eventually get ovarian cancer themselves.[25] This corresponds to a risk increased by a bit more than twice that of ovarian cancer in the general population.[26] 7 out of 100 women with two or more relatives with ovarian cancer will eventually get ovarian cancer.[25] The other way around, 10 to 20 percent of women with ovarian cancer have a first- or second-degree relative with either breast or ovarian cancer. Mutations in either of two major susceptibility genes, breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2), confer a lifetime risk of breast cancer of between 60 and 85 percent and a lifetime risk of ovarian cancer of between 15 and 40 percent. However, mutations in these genes account for only 2 to 3 percent of all breast cancers.[27]
A strong family history of uterine cancer, colon cancer, or other gastrointestinal cancers may indicate the presence of a syndrome known as hereditary nonpolyposis colorectal cancer (HNPCC, also known as Lynch syndrome), which confers a higher risk for developing ovarian cancer. Patients with strong genetic risk for ovarian cancer may consider the use of prophylactic, i.e. preventative, oophorectomy the surgical removal of both ovaries, after completion of childbearing years. Prophylactic oophorectomy significantly reduces the chances of developing both breast cancer and ovarian cancer in people at high risk. Women with BRCA gene mutations usually also have their fallopian tubes removed at the same time (salpingo-oophorectomy), since they also have an increased risk of fallopian tube cancer.[28]
Hereditary breast-ovarian cancer syndromes (HBOC) produce higher than normal levels of breast cancer and ovarian cancer in genetically related families (either one individual suffered from both, or several individuals in the families suffered from one or the other disease). The hereditary factors may be proven or suspected to cause the pattern of breast and ovarian cancer occurrences in the family.
Alcohol consumption does not appear to be related to ovarian cancer.[29]
A Swedish study, which followed more than 61,000 women for 13 years, has found a significant link between milk consumption and ovarian cancer. According to the BBC, "[Researchers] found that milk had the strongest link with ovarian cancer—those women who drank two or more glasses a day were at double the risk of those who did not consume it at all, or only in small amounts."[30] Recent studies have shown that women in sunnier countries have a lower rate of ovarian cancer, which may have some kind of connection with exposure to Vitamin D.[31]
Other factors that have been investigated, such as talc use,[32] asbestos exposure, high dietary fat content, and childhood mumps infection, are controversial[33] and have not been definitively proven; moreover, such risk factors may in some cases be more likely to be correlated with cancer in individuals with specific genetic makeups.[34]
Women who have had children are less likely to develop ovarian cancer than women who have not, and breastfeeding may also reduce the risk of certain types of ovarian cancer. Tubal ligation and hysterectomy reduce the risk and removal of both tubes and ovaries (bilateral salpingo-oophorectomy) dramatically reduces the risk of not only ovarian cancer but breast cancer also.[35] A hysterectomy that does not include the removal of the ovaries has a one-third reduced risk of developing ovarian cancer,[36] it also has no higher risk of developing other types of cancer, heart disease or hip fractures, researchers from the University of California at San Francisco revealed in the journal Archives of Internal Medicine.[37]
A long-standing hypothesis that has considerable support via animal model studies is the incessant ovulation hypothesis. According to this, "repeated cycles of ovulation-induced trauma and repair of the OSE [ovarian surface epithelium] at the site of ovulation, without pregnancy-induced rest periods, contributes to ovarian cancer development."[38] Analysis of 316 high-grade serous ovarian adenocarcinomas found that the TP53 gene was mutated in 96% of cases.[39] Other genes commonly mutated were NF1, BRCA1, BRCA2, RB1 and cyclin-dependent kinase 12 (CDK12).
Diagnosis of ovarian cancer starts with a physical examination (including a pelvic examination), a blood test (for CA-125 and sometimes other markers), and transvaginal ultrasound. The diagnosis must be confirmed with surgery to inspect the abdominal cavity, take biopsies (tissue samples for microscopic analysis) and look for cancer cells in the abdominal fluid.
Ovarian cancer at its early stages (I/II) is difficult to diagnose until it spreads and advances to later stages (III/IV). This is because most symptoms are non-specific and thus of little use in diagnosis.[40] The serum BHCG level should be measured in any female in whom pregnancy is a possibility. In addition, serum alpha-fetoprotein (AFP) and lactate dehydrogenase (LDH) should be measured in young girls and adolescents with suspected ovarian tumors because the younger the patient, the greater the likelihood of a malignant germ cell tumor.
When an ovarian malignancy is included in the list of diagnostic possibilities, a limited number of laboratory tests are indicated. A complete blood count (CBC) and serum electrolyte test should be obtained in all patients. A blood test called CA-125 is useful in differential diagnosis and in follow up of the disease, but it by itself has not been shown to be an effective method to screen for early-stage ovarian cancer due to its unacceptable low sensitivity and specificity. Another tests used is OVA1.[41]
Current research is looking at ways to combine tumor markers proteomics along with other indicators of disease (i.e. radiology and/or symptoms) to improve accuracy. The challenge in such an approach is that the disparate prevalence of ovarian cancer means that even testing with very high sensitivity and specificity will still lead to a number of false positive results (i.e. performing surgical procedures in which cancer is not found intra-operatively). However, the contributions of proteomics are still in the early stages and require further refining. Current studies on proteomics mark the beginning of a paradigm shift towards individually tailored therapy.[42]
A pelvic examination and imaging including CT scan[43] and trans-vaginal ultrasound are essential. Physical examination may reveal increased abdominal girth and/or ascites (fluid within the abdominal cavity). Pelvic examination may reveal an ovarian or abdominal mass. The pelvic examination can include a Rectovaginal component for better palpation of the ovaries. For very young patients, magnetic resonance imaging may be preferred to rectal and vaginal examination.
To definitively diagnose ovarian cancer, a surgical procedure to take a look into the abdomen is required. This can be an open procedure (laparotomy, incision through the abdominal wall) or keyhole surgery (laparoscopy). During this procedure, suspicious areas will be removed and sent for microscopic analysis. Fluid from the abdominal cavity can also be analysed for cancerous cells. If there is cancer, this procedure can also determine its spread (which is a form of tumor staging).
A widely recognized method of estimating the risk of malignant ovarian cancer based on initial workup is the risk of malignancy index (RMI).[44]
It is recommended that women with an RMI score over 200 should be referred to a center with experience in ovarian cancer surgery.[45]
The RMI is calculated as follows:[45]
There are two methods to determine the ultrasound score and menopausal score, with the resultant RMI being called RMI 1 and RMI 2, respectively, depending on what method is used:[45]
| Feature | RMI 1 | RMI 2 |
|---|---|---|
|
Ultrasound abnormalities:
|
|
|
| Menopausal score |
|
|
| CA-125 | Quantity in U/ml | Quantity in U/ml |
An RMI 2 of over 200 has been estimated to have a sensitivity of 74 to 80%, a specificity of 89 to 92% and a positive predictive value of around 80% of ovarian cancer.[45] RMI 2 is regarded as more sensitive than RMI 1.[45]
Ovarian cancer is classified according to the histology of the tumor, obtained in a pathology report. Histology dictates many aspects of clinical treatment, management, and prognosis.
According to SEER, the types of ovarian cancers in women age 20+ are as follows:[46]
| Percent of ovarian cancers |
Histology | 5 year RSR |
|---|---|---|
| 89.7 | Surface epithelial-stromal tumor (Adenocarcinoma) | 54.4 |
| 26.4 | Papillary serous cystadenocarcinoma | 21.0 |
| 15.9 | "Borderline" adenocarcinoma (underestimated b/c short data collection interval) |
98.2 |
| 12.6 | Adenocarcinoma, not otherwise specified | 18.3 |
| 9.8 | Endometrioid tumor | 70.9 |
| 5.8 | Serous cystadenocarcinoma | 44.2 |
| 5.5 | Papillary | 21.0 |
| 4.2 | Mucinous cystadenocarcinoma | 77.7 |
| 4.0 | Clear-cell ovarian tumor | 61.5 |
| 3.4 | Mucinous adenocarcinoma | 49.1 |
| 1.3 | Cystadenocarcinoma | 50.7 |
| 5.5 | Carcinoma | |
| 4.1 | Carcinoma not otherwise specified | 26.8 |
| 1.1 | Sex cord-stromal tumour | 87.8 |
| 0.3 | Other carcinomas, specified | 37.3 |
| 1.7 | Mullerian tumor | 29.8 |
| 1.5 | Germ cell tumor | 91.0 |
| 0.8 | Teratoma | 89.1 |
| 0.5 | Dysgerminoma | 96.8 |
| 0.3 | Other, specified | 85.1 |
| 0.6 | Not otherwise specified | 23.0 |
| 0.5 | Epidermoid (Squamous cell carcinoma) | 51.3 |
| 0.2 | Brenner tumor | 67.9 |
| 0.2 | Other, specified | 71.7 |
Ovarian cancer can also be a secondary cancer, the result of metastasis from a primary cancer elsewhere in the body. 7% of ovarian cancers are due to metastases while the rest are primary cancers. Common primary cancers are breast cancer and gastrointestinal cancer. (A common mistake is to name all peritoneal metastases from any gastrointestinal cancer as a Krukenberg tumor,[47] but this is only the case if it originates from primary gastric cancer). Surface epithelial-stromal tumor can originate in the peritoneum (the lining of the abdominal cavity), in which case the ovarian cancer is secondary to primary peritoneal cancer, but treatment is basically the same as for primary surface epithelial-stromal tumor involving the peritoneum.[48]
Ovarian cancer is bilateral in 25% of cases.[49]
Ovarian cancer staging is by the FIGO staging system and uses information obtained after surgery, which can include a total abdominal hysterectomy, removal of (usually) both ovaries and fallopian tubes, (usually) the omentum, and pelvic (peritoneal) washings for cytopathology. The AJCC stage is the same as the FIGO stage. The AJCC staging system describes the extent of the primary Tumor (T), the absence or presence of metastasis to nearby lymph Nodes (N), and the absence or presence of distant Metastasis (M).[50]
Stage 1 ovarian cancer
Stage 2 ovarian cancer
Stage 3 ovarian cancer
Stage 4 ovarian cancer
Para-aortic lymph node metastases are considered regional lymph nodes (Stage IIIC). As there is only one para-aortic lymph node intervening before the thoracic duct on the right side of the body, the ovarian cancer can rapidly spread to distant sites such as the lung.
The AJCC/TNM staging system includes three categories for ovarian cancer, T, N and M. The T category contains three other subcategories, T1, T2 and T3, each of them being classified according to the place where the tumor has developed (in one or both ovaries, inside or outside the ovary). The T1 category of ovarian cancer describes ovarian tumors that are confined to the ovaries, and which may affect one or both of them. The sub-subcategory T1a is used to stage cancer that is found in only one ovary, which has left the capsule intact and which cannot be found in the fluid taken from the pelvis. Cancer that has not affected the capsule, is confined to the inside of the ovaries and cannot be found in the fluid taken from the pelvis but has affected both ovaries is staged as T1b. T1c category describes a type of tumor that can affect one or both ovaries, and which has grown through the capsule of an ovary or it is present in the fluid taken from the pelvis. T2 is a more advanced stage of cancer. In this case, the tumor has grown in one or both ovaries and is spread to the uterus, fallopian tubes or other pelvic tissues. Stage T2a is used to describe a cancerous tumor that has spread to the uterus or the fallopian tubes (or both) but which is not present in the fluid taken from the pelvis. Stages T2b and T2c indicate cancer that metastasized to other pelvic tissues than the uterus and fallopian tubes and which cannot be seen in the fluid taken from the pelvis, respectively tumors that spread to any of the pelvic tissues (including uterus and fallopian tubes) but which can also be found in the fluid taken from the pelvis. T3 is the stage used to describe cancer that has spread to the peritoneum. This stage provides information on the size of the metastatic tumors (tumors that are located in other areas of the body, but are caused by ovarian cancer). These tumors can be very small, visible only under the microscope (T3a), visible but not larger than 2 centimeters (T3b) and bigger than 2 centimeters (T3c).
This staging system also uses N categories to describe cancers that have or not spread to nearby lymph nodes. There are only two N categories, N0 which indicates that the cancerous tumors have not affected the lymph nodes, and N1 which indicates the involvement of lymph nodes close to the tumor.
The M categories in the AJCC/TNM staging system provide information on whether the ovarian cancer has metastasized to distant organs such as liver or lungs. M0 indicates that the cancer did not spread to distant organs and M1 category is used for cancer that has spread to other organs of the body.
The AJCC/TNM staging system also contains a Tx and a Nx sub-category which indicates that the extent of the tumor cannot be described because of insufficient data, respectively the involvement of the lymph nodes cannot be described because of the same reason.
The ovarian cancer stages are made up by combining the TNM categories in the following manner:
In addition to being staged, like all cancers ovarian cancer is also graded. The histologic grade of a tumor measures how abnormal or malignant its cells look under the microscope.[51] There are four grades indicating the likelihood of the cancer to spread and the higher the grade, the more likely for this to occur. Grade 0 is used to describe non-invasive tumors. Grade 0 cancers are also referred to as borderline tumors.[51] Grade 1 tumors have cells that are well differentiated (look very similar to the normal tissue) and are the ones with the best prognosis. Grade 2 tumors are also called moderately well differentiated and they are made up by cells that resemble the normal tissue. Grade 3 tumors have the worst prognosis and their cells are abnormal, referred to as poorly differentiated.
Tubal ligation appears to reduce the risk of ovarian cancer in women who carry the BRCA1 (but not BRCA2) gene.[52] The use of birth control pills decreases the risk of ovarian cancer by about half a percentage point (or about in half in those who are on them for more than 10 years).[53]
Screening is not recommended using either CA-125 measurements or ultrasound in women who are at average risk.[54] This is because there is no good evidence which shows that screening tests measuring CA-125 or doing ultrasound detect cancer any sooner or otherwise result in better outcomes for women with average risk.[55][56] Screening for any type of cancer must be accurate and reliable—it needs to accurately detect the disease and it must not give false positive results in people who do not have cancer. However, in some countries such as the UK, women who are likely to have an increased risk of ovarian cancer (for example if they have a family history of the disease) can be offered individual screening through their doctors, although this will not necessarily detect the disease at an early stage.
Ovarian cancer has low prevalence and screening of women with average risk is more likely to give ambiguous results than detect a problem which requires treatment.[55] Because ambiguous results are more likely than detection of a treatable problem, and because the usual response to ambiguous results is invasive interventions, in women of average risk the potential harms of having screening without an indication outweigh the potential benefits.[55] The purpose of screening is to diagnose ovarian cancer at an early stage, when it is more likely to be treated successfully. However, the development of the disease is not fully understood, and it has been argued that early-stage cancers may not always develop into late-stage disease.[56] With any screening technique there are risks and benefits that need to be carefully considered, and health authorities need to assess these before introducing any ovarian cancer screening programmes.
Treatment usually involves chemotherapy and surgery, and sometimes radiotherapy.[57]
Surgical treatment may be sufficient for malignant tumors that are well-differentiated and confined to the ovary. Addition of chemotherapy may be required for more aggressive tumors that are confined to the ovary. For patients with advanced disease a combination of surgical reduction with a combination chemotherapy regimen is standard. Borderline tumors, even following spread outside of the ovary, are managed well with surgery, and chemotherapy is not seen as useful.
Surgery is the preferred treatment and is frequently necessary to obtain a tissue specimen for differential diagnosis via its histology. Surgery performed by a specialist in gynecologic oncology usually results in an improved result.[58] Improved survival is attributed to more accurate staging of the disease and a higher rate of aggressive surgical excision of tumor in the abdomen by gynecologic oncologists as opposed to general gynecologists and general surgeons.
The type of surgery depends upon how widespread the cancer is when diagnosed (the cancer stage), as well as the presumed type and grade of cancer. The surgeon may remove one (unilateral oophorectomy) or both ovaries (bilateral oophorectomy), the fallopian tubes (salpingectomy), and the uterus (hysterectomy). For some very early tumors (stage 1, low grade or low-risk disease), only the involved ovary and fallopian tube will be removed (called a "unilateral salpingo-oophorectomy," USO), especially in young females who wish to preserve their fertility.
In advanced malignancy, where complete resection is not feasible, as much tumor as possible is removed (debulking surgery). In cases where this type of surgery is successful (i.e. < 1 cm in diameter of tumor is left behind ["optimal debulking"]), the prognosis is improved compared to patients where large tumor masses (> 1 cm in diameter) are left behind. Minimally invasive surgical techniques may facilitate the safe removal of very large (greater than 10 cm) tumors with fewer complications of surgery.[59]
Chemotherapy has been a general standard of care for ovarian cancer for decades, although with highly variable protocols.[60] Chemotherapy is used after surgery to treat any residual disease, if appropriate. This depends on the histology of the tumor; some kinds of tumor (particularly teratoma) are not sensitive to chemotherapy. In some cases, there may be reason to perform chemotherapy first, followed by surgery.
For patients with stage IIIC epithelial ovarian adenocarcinomas who have undergone successful optimal debulking, a recent clinical trial demonstrated that median survival time is significantly longer for patient receiving intraperitoneal (IP) chemotherapy.[61] Patients in this clinical trial reported less compliance with IP chemotherapy and fewer than half of the patients received all six cycles of IP chemotherapy. Despite this high "drop-out" rate, the group as a whole (including the patients that didn't complete IP chemotherapy treatment) survived longer on average than patients who received intravenous chemotherapy alone.
Some specialists believe the toxicities and other complications of IP chemotherapy will be unnecessary with improved IV chemotherapy drugs currently being developed.
Although IP chemotherapy has been recommended as a standard of care for the first-line treatment of ovarian cancer, the basis for this recommendation has been challenged, and it has not yet become standard treatment for stage III or IV ovarian cancer.[62][63]
Radiation therapy is not effective for advanced stages because when vital organs are in the radiation field, a high dose cannot be safely delivered. Radiation therapy is then commonly avoided in such stages as the vital organs may not be able to withstand the problems associated with these ovarian cancer treatments.[64]
Immune-cell therapies have been reported which have been administered with chemo and/or radiotherapy with efficacy in several patients.[65][66]
Specific follow-up depends on, for example, the type and stage of ovarian cancer, the treatment, as well as the presence of any symptoms. There is usually a check-up appointment approximately every 2 to 3 months initially, followed by twice per year for up to 5 years.[67] For epithelial ovarian cancers, the most common test upon follow-up is CA-125 level. However, treatment based only on elevated CA-125 levels and not any symptoms can increase side effects without any prolongation of life, so the implication of the outcome of a CA-125 test should be discussed before taking it.[68]
Recommendations for the use of the CA-125 antigen in monitoring extent of cancer after treatment include:[69]
For women with germ cell tumors, follow-up tests generally include alpha-fetoprotein (AFP) and/or human chorionic gonadotropin (HCG).[68] For women with stromal cancers, tests including hormones like estrogen, testosterone, and inhibin are sometimes helpful.[68]
Women with ovarian cancer should not have routine surveillance imaging to monitor the cancer unless new symptoms appear or tumor markers begin rising.[70] Imaging without these indications is discouraged because it is unlikely to detect a recurrence, improve survival, and because it has its own costs and side effects.[70]
Palliative care has been defined by the World Health Organization as "an interdisciplinary approach that supports and improves the quality of life (QOL) of patients and their families facing the problems associated with a life-threatening illness, such as cancer, through the prevention and treatment of distressing symptoms while addressing the psychological, social, and spiritual aspects of patient care."[71] It has been recommended palliative care as part of the treatment plan for any person with advanced ovarian cancer or patients with significant symptoms.[72]
Palliative care can entail treatment of symptoms and complications of the cancer, including pain, nausea, constipation, ascites, bowel obstruction, edema and mucositis. Especially if the cancer advances and becomes incurable, treatment of symptoms becomes one of the main goals of therapy. Palliative care can also entail helping with decision making such as if or when hospice care is appropriate, and the preferred place for the patient at end of life care.[71]
Ovarian cancer usually has a relatively poor prognosis. It is disproportionately deadly because it lacks any clear early detection or screening test, meaning that most cases are not diagnosed until they have reached advanced stages. Women with advanced ovarian cancer or a relapse should get palliative care immediately and if appropriate a referral to a palliative care physician.[74]
More than 60% of women presenting with this cancer have stage III or stage IV cancer, when it has already spread beyond the ovaries. Ovarian cancers shed cells into the naturally occurring fluid within the abdominal cavity. These cells can then implant on other abdominal (peritoneal) structures, included the uterus, urinary bladder, bowel and the lining of the bowel wall omentum forming new tumor growths before cancer is even suspected.
The five-year survival rate for all stages of ovarian cancer is 47%.[75] For cases where a diagnosis is made early in the disease, when the cancer is still confined to the primary site, the five-year survival rate is 92.7%.[76]
Ovarian cancer is the second most common gynecologic cancer and the deadliest in terms of absolute number.[63] It caused nearly 14,000 deaths in the United States alone in 2010. While the overall five-year survival rate for all cancers combined has improved significantly: 68% for the general population diagnosed in 2001 (compared to 50% in the 1970s),[75] ovarian cancer has a poorer outcome with a 47% survival rate (compared to 38% in the late 1970s).[75]
These cells can implant on other abdominal (peritoneal) structures, including the uterus, urinary bladder, bowel, lining of the bowel wall (omentum) and, less frequently, to the lungs.
Age-standardized death from ovarian cancer per 100,000 inhabitants in 2004.[77]
Globally, as of 2010, approximately 160,000 people died from ovarian cancer, up from 113,000 in 1990.[78] The disease is more common in industrialized nations, with the exception of Japan. In the United States, females have a 1.4% to 2.5% (1 out of 40-60 women) lifetime chance of developing ovarian cancer. Older women are at highest risk.[79] More than half of the deaths from ovarian cancer occur in women between 55 and 74 years of age and approximately one quarter of ovarian cancer deaths occur in women between 35 and 54 years of age.
In 2010, in the United States, it is estimated that 21,880 new cases were diagnosed and 13,850 women died of ovarian cancer. The risk increases with age and decreases with numbers of pregnancy. Lifetime risk is about 1.6%, but women with affected first-degree relatives have a 5% risk. Women with a mutated BRCA1 or BRCA2 gene carry a risk between 25% and 60% depending on the specific mutation.[80] Ovarian cancer is the second most common cancer in women (affecting about 1/70) and the leading cause of death from gynecologic cancer, as well as the deadliest (1% of all women die of it). It is the fifth leading cause of cancer-related deaths in women, causing an estimated 15,000 deaths in 2008. Incidence is higher in developed countries.[63]
From 2004–2008, the median age at diagnosis for cancer of the ovary was 63 years of age. Approximately 1.2% were diagnosed under age 20; 3.5% between 20 and 34; 7.3% between 35 and 44; 19.1% between 45 and 54; 23.1% between 55 and 64; 19.7% between 65 and 74; 18.2% between 75 and 84; and 8.0% 85+ years of age. 10-year relative survival ranges from 84.1% in stage IA to 10.4% in stage IIIC.[46][76]
The age-adjusted incidence rate was 12.8 per 100,000 women per year. These rates are based on cases diagnosed in 2004–2008 from 17 SEER geographic areas.[46]
Ovarian tumors have been reported in mares. Reported tumor types include teratoma,[81][82] cystadenocarcinoma,[83] and particularly granulosa cell tumor.[84][85][86][87][88]
Researchers are assessing different ways to screen for ovarian cancer. Screening tests that could potentially be used alone or in combination for routine screening include the CA-125 marker and transvaginal ultrasound. Doctors can measure the levels of the CA-125 protein in a woman’s blood—high levels could be a sign of ovarian cancer, but this is not always the case. And not all women with ovarian cancer have high CA-125 levels. Transvaginal ultrasound involves using an ultrasound probe to scan the ovaries from inside the vagina, giving a clearer image than scanning the abdomen. The UK Collaborative Trial of Ovarian Cancer Screening is testing a screening technique that combines CA-125 blood tests with transvaginal ultrasound. Several large studies are ongoing, but none have identified an effective technique.[89] In 2009, however, early results from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) showed that a technique combining annual CA-125 tests with ultrasound imaging did help to detect the disease at an early stage.[90] However, it's not yet clear if this approach could actually help to save lives—the full results of the trial will be published in 2015.
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| リンク元 | 「卵巣癌」 |
| 関連記事 | 「ovarian」 |
・予後：治療しなければ予後不良。増殖速度は中等度でリンパ節転移しやすい。
・予後：容易。進行遅く、転移も少ない。
| 名称 | 卵巣癌の中の頻度 | 疫学 | 病理 | 類似性 | 予後 | 卵巣チョコレート嚢胞 との関連 |
| 漿液性腺癌[漿液性嚢胞腺癌] | 50% | 平均55歳 | 小型で細胞質に乏しい。樹枝状に分枝。乳頭状腺癌 | 卵巣表皮上皮、卵管上皮細胞 | 比較的良好 | |
| 粘液性腺癌[粘液性嚢胞腺癌] | 10-15% | 平均44歳 | 豊富な粘液をもつ多房構造や15cmを超える巨大腫瘤 | 子宮頸部粘膜上皮 腸上皮に類似 |
抗癌剤感受性低く、進行癌は予後不良 | |
| 類内膜腺癌 | 10-15% | 非妊時子宮内膜に類似 | ○ | |||
| 明細胞腺癌 | 15-20% | 子宮内膜症合併 | 胞体は明るくグリコーゲンに富む。 | 妊娠子宮内膜に類似 嚢胞乳頭状構造 |
プラチナ感受性悪く予後不良 | ○ |
| 名称 | AFP | CA125 | CA72-4 | BFP | CEA |
| 漿液性腺癌[漿液性嚢胞腺癌] | ○ | ○ | |||
| 粘液性腺癌[粘液性嚢胞腺癌] | ○ | ||||
| 類内膜腺癌 | ○ | ||||
| 明細胞腺癌 | |||||
| 卵黄嚢腫瘍 | ○ | ||||
| 転移性卵巣癌 | ○ | ○ |
| CA125 | 漿液性嚢胞腺癌 | 類内膜腺癌 | 移行上皮癌 | |
| CEA | CA19-9 | 粘液性嚢胞腺癌 | ||
| エストロゲン | 顆粒膜細胞腫 | 莢膜細胞腫 | ||
| アンドロゲン | セルトリ・間質細胞腫 | ライディッヒ細胞種 | ||
| CA19-9 | SCC | 奇形腫 | ||
| AFP | 卵黄嚢腫瘍 | 胎芽性癌 | ||
| hCG | 絨毛癌 | 胎芽性癌 | 未分化胚細胞腫 | |
| LDH | 未分化胚細胞腫 | |||
| CEA | クルケンベルグ腫瘍 | |||