Ovarian cancer facts for kids
Quick facts for kids Ovarian cancer |
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| Micrograph of a mucinous ovarian carcinoma stained by H&E | |
| Symptoms | Early: vague Later: bloating, pelvic pain, constipation, abdominal swelling, loss of appetite |
| Usual onset | Usual age of diagnosis 63 years old |
| Risk factors | Never having children, hormone therapy after menopause, fertility medication, obesity, genetics |
| Diagnostic method | Tissue biopsy |
| Treatment | Surgery, radiation therapy, chemotherapy |
| Prognosis | Five-year survival rate c. 49% (US) |
| Frequency | 1.2 million (2015) |
| Deaths | 161,100 (2015) |
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from communicating nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they have the ability to divide and form tumors. These cells can also invade or spread to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver.
The risk of ovarian cancer increases with age. Most cases of ovarian cancer develop after menopause. It is also more common in women who have ovulated more over their lifetime. This includes those who have never had children, those who began ovulation at a younger age and those who reach menopause at an older age. Other risk factors include hormone therapy after menopause, fertility medication, and obesity. Factors that decrease risk include pregnancy, and breast feeding. About 10% of cases are related to inherited genetic risk; women with mutations in the genes BRCA1 or BRCA2 have about a 50% chance of developing the disease. Some family cancer syndromes such as hereditary nonpolyposis colon cancer and Peutz-Jeghers syndrome also increase the risk of developing ovarian cancer. Epithelial ovarian carcinoma is the most common type of ovarian cancer, comprising more than 95% of cases. There are five main subtypes of ovarian carcinoma, of which high-grade serous carcinoma (HGSC) is the most common. A diagnosis of ovarian cancer is confirmed through a biopsy of tissue, usually removed during surgery.
Screening is not recommended in women who are at average risk, as evidence does not support a reduction in death and the high rate of false positive tests may lead to unneeded surgery, which is accompanied by its own risks. Those at very high risk may have their ovaries removed as a preventive measure. If caught and treated in an early stage, ovarian cancer is often curable. Treatment usually includes some combination of surgery, radiation therapy, and chemotherapy. Outcomes depend on the extent of the disease, the subtype of cancer present, and other medical conditions. The overall five-year survival rate in the United States is 49%. Outcomes are worse in the developing world.
In 2020, new cases occurred in approximately 313,000 women. In 2019 it resulted in 13,445 deaths in the United States. Death from ovarian cancer increased globally between 1990 and 2017 by 84.2%. Ovarian cancer is the second-most common gynecologic cancer in the United States. It causes more deaths than any other cancer of the female reproductive system. Among women it ranks fifth in cancer-related deaths. The typical age of diagnosis is 63. Death from ovarian cancer is more common in North America and Europe than in Africa and Asia. In the United States, it is more common in White and Hispanic women than Black or American Indian women.
Epidemiology
Globally, in 2018, the incidence of ovarian cancer was 6.6 per 100,000 and mortality was 3.9. Globally, about 160,000 people died from ovarian cancer in 2010. This was an increase from 113,000 in 1990. The number of new cases per year in Europe is approximately 5–15 per 100,000 women. In Europe, Lithuania, Latvia, Ireland, Slovakia, and the Czech Republic have the highest incidences of ovarian cancer, whereas Portugal and Cyprus have the lowest incidences. In 2008, the five-year survival rate was 44%. This has increased since 1977 when the survival rate was 36%.
United States
In 2022, in the United States, an estimated 19,880 new cases were diagnosed and 12,810 women died of ovarian cancer. The 5-year relative survival rate is 49.7%. Around 57% cases have metastasized at the time of diagnosis.
In 2014, over 220,000 diagnoses of epithelial ovarian cancer were made yearly. The overall lifetime risk in the US is around 1.6% In the US, ovarian cancer affects 1.3–1.4% and is the cause of death of about 1% of women. In the United States, it is also the fifth-most common cancer in women but the fourth-most common cause of cancer death. This decrease made it the ninth-most common cancer in women.
United Kingdom
It is the 5th-most common cancer in UK women (around 7,100 were diagnosed in 2011) and the 5th-most common cause of cancer death in women (around 4,300 died in 2012). The incidence rate over the whole UK population is 21.6 per 100,000.
As of 2014, the UK saw approximately 7,000–7,100 yearly diagnoses with 4,200 deaths. A 2022 article from The Times put the estimate at 7,500 new cases yearly in Britain. Early symptoms are often mistaken for common conditions such as cystitis or irritable bowel syndrome, and about 40 per cent of UK women wrongly believe that cervical screening detects ovarian cancer, an increase from 30 per cent in 2016. Ashkenazi Jewish women carry mutated BRCA alleles five times more often than the rest of the population, giving them a higher risk developing ovarian cancer.
Older women
In the US, the incidence rate in women over 50 is approximately 33 per 100,000. The rate of ovarian cancer between 1993 and 2008 decreased in women of the 40–49 age cohort and in the 50–64 age cohort. Ovarian cancer is most commonly diagnosed after menopause, between the ages of 60 and 64. Ninety percent of ovarian cancer occurs in women over the age of 45 and 80% in women over 50. Older women are more likely to present with advanced ovarian cancer.
In pregnancy
Malignant germ cell tumors are the type of ovarian cancer most likely to occur during pregnancy. They are typically diagnosed when an adnexal mass is found on examination (in 1–2% of all pregnancies), a tumor is seen on ultrasound, or the parent's level of alpha-fetoprotein is elevated. Dermoid cysts and dysgerminomas are the most common germ cell tumors during pregnancy. Germ cell tumors diagnosed during pregnancy are unlikely to have metastasized and can be treated by surgery and, in some cases, chemotherapy, which carries the risk of birth defects. Yolk sac tumors and immature teratomas grow particularly quickly and are usually treated with chemotherapy even during pregnancy; however, dysgerminomas that have been optimally debulked may be treated after childbirth.
Other animals
Ovarian tumors have been reported in equine mares. Reported tumor types include teratoma, cystadenocarcinoma, and particularly granulosa cell tumor.
Research
Screening
Screening by hysteroscopy to obtain cell samples obtained for histological examination is being developed. This is similar to the current pap smear that is used to detect cervical cancer. The UK Collaborative Trial of Ovarian Cancer Screening is testing a screening technique that combines CA-125 blood tests with transvaginal ultrasound. Other studies suggest that this screening procedure may be effective. Although results published in 2015 were not conclusive, there was some evidence that screening may save lives in the long-term. As a result, the trial has been extended and will publish definitive results at the end of 2019. One major problem with screening is no clear progression of the disease from stage I (noninvasive) to stage III (invasive) is seen, and it may not be possible to find cancers before they reach stage III. Another problem is that screening methods tend to find too many suspicious lesions, most of which are not cancer, but malignancy can only be assessed with surgery. The ROCA method combined with transvaginal ultrasonography is being researched in high-risk women to determine if it is a viable screening method. It is also being investigated in normal-risk women as it has shown promise in the wider population. Studies are also in progress to determine if screening helps detect cancer earlier in people with BRCA mutations.
Prognosis research
Research into various prognostic factors for ovarian cancer is also going on. Recent research shows that thrombocytosis predicts lower survival and higher stage cancer. Ongoing research is also investigating the benefits of surgery for recurrent ovarian cancer.
Immunotherapy
While an active area of research, as of 2018 there is no good evidence that immunotherapy is effective for ovarian cancer. However, trials of the antibody and VEGF inhibitor bevacizumab, which can slow the growth of new blood vessels in the cancer, have shown promising results, especially in combination with pazopanib, which also slows the process of blood vessel growth. Bevacizumab has been particularly effective in preliminary studies on stage-III and -IV cancer and has been cited as having at least a 15% response rate. It is being investigated particularly in mucinous ovarian cancers.
Pharmacology
mTOR inhibitors were a highly investigated potential treatment in the 2000s and 2010s, but the side effects of these drugs (particularly hyperglycemia and hyperlipidemia) were not well tolerated and the survival benefit not confirmed. PI3 kinase inhibitors have been of interest, but they tend to be highly toxic and cause diarrhea. Another investigated drug is selumetinib, a MAPK inhibitor. It improved survival, but did not correlate with any mutations found in tumors.
Bevacizumab can also be combined with platinum chemotherapy, a combination that has had positive preliminary results in PFS, but equivocal results regarding overall survival. One disadvantage to these treatments is the side effect profile, which includes high blood pressure and proteinuria. The drug can also exacerbate bowel disease, leading to fistulae or bowel perforation. Vintafolide, which consists of an antifolate conjugated with vinblastine, is also in clinical trials; it may prove beneficial because folate receptors are overexpressed in many ovarian cancers. Another potential immunotherapy is trastuzumab, which is active against tumors positive for Her2/neu mutations. Other angiogenesis inhibitors are also being investigated as potential ovarian cancer treatments. Combretastatin and pazopanib are being researched in combination for recurrent ovarian cancer. Trebananib and tasquinimod are other angiogenesis inhibitors being investigated. The monoclonal antibody farletuzumab is being researched as an adjuvant to traditional chemotherapy. Another type of immunotherapy involves vaccines, including TroVax.
An alternative to BEP chemotherapy, a regimen of 3 cycles of carboplatin and etoposide, is a current topic of research for germ cell malignancies.
Intraperitoneal chemotherapy has also been under investigation during the 2000s and 2010s for its potential to deliver higher doses of cytotoxic agent to tumors. Preliminary trials with cisplatin and paclitaxel have shown it is not well tolerated, but does improve survival, and more tolerable regimens are being researched. Cisplatin and paclitaxel are both being researched as intraperitoneal chemotherapy agents. A specific chemotherapy regimen for rare clear-cell cancers is also under investigation: irinotecan combined with cisplatin.
PARP inhibitors have also shown promise in early trials, particularly in people with BRCA gene mutations, since the BRCA protein interacts with the PARP pathway. It is also being studied in recurrent ovarian cancer in general, where preliminary studies have shown longer PFS. Specifically, olaparib has shown greater survival compared to doxorubicin, though this treatment is still being investigated. It is not clear yet which biomarkers are predictive of responsiveness to PARP inhibitors. Rucaparib is another PARP inhibitor being researched in BRCA-positive and BRCA-negative recurrent advanced ovarian cancer. Niraparib is a PARP inhibitor being tested in BRCA-positive recurrent ovarian cancer.
Tyrosine kinase inhibitors are another investigational drug class that may have applications in ovarian cancer. Angiogenesis inhibitors in the receptor tyrosine kinase inhibitor group, including pazopanib, cediranib, and nintedanib, have also been shown to increase progression free survival (PFS), but their benefit for overall survival has not been investigated as of 2015. Preliminary research showed that cediranib combined with platins in recurrent ovarian cancer increased the time to second recurrence by 3–4 months and increased survival by 3 months. MK-1775 is a tyrosine kinase inhibitor that is being used in combination with paclitaxel and carboplatin in platinum-sensitive cancers with p53 mutations. Nintedanib is being researched as a potential therapy in combination with cyclophosphamide for people with recurrences.
Histone deacetylase inhibitors (HDACi) are another area of research.
Hormones and radiation
Hormone therapies are a topic of current research in ovarian cancer, particularly, the value of certain medications used to treat breast cancer. These include tamoxifen, letrozole, and anastrozole. Preliminary studies have showed a benefit for tamoxifen in a small number of people with advanced ovarian cancer. Letrozole may help to slow or stop growth of estrogen receptor positive ovarian cancer. Anastrozole is being investigated in postmenopausal people with estrogen receptor-positive cancer.
Research into mitigating side effects of ovarian cancer treatment is also ongoing. Radiation fibrosis, the formation of scar tissue in an area treated with radiation, may be relieved with hyperbaric oxygen therapy, but research has not been completed in this area. Treatment of ovarian cancer may also cause people to experience psychiatric difficulties, including depression. Research is ongoing to determine how counseling and psychotherapy can help people who have ovarian cancer during treatment.
Inflammation
There are some indications that pelvic inflammatory disease may be associated with ovarian cancer, especially in non-western countries. It may be due to the inflammatory process present with pelvic inflammatory disease.
Clinical trials
Clinical trials are monitored and funded by US governmental organizations to test treatment options to see if they are safe and effective. These include NIH Clinical Research Trials and You (National Institutes of Health), Learn About Clinical Trials (National Cancer Institute), Search for Clinical Trials (National Cancer Institute), ClinicalTrials.gov (National Institutes of Health). Clinical trials are also conducted in Canada.
