Ovarian cancer is the fifth most common cancer in women after lung, breast, colorectal, and pancreatic cancers. It accounts for only three percent of cancer in women, and fortunately, there has been a decrease in the incidence of this type of cancer by about 1% in the last twenty years. Unfortunately, the diagnosis is usually late, as there are very subtle and often protean signs and symptoms. Ovarian cancer is not only a cancer of old age, it can occur at any age, even in childhood, however, the incidence of this cancer increases significantly after 50 years.
There are certain risk factors for ovarian cancer, the main ones being family history and some associated genetic syndromes. A blood relative with ovarian cancer increases her female relative’s risk by 5% for this cancer. There is a hereditary breast and ovarian cancer syndrome that occurs in one in 500 women and, being an autosomal dominant genetic disorder, results in the mutation of the BRCA1 and/or BRCA2 gene. The other is Lynch II syndrome, a hereditary non-polyposis colorectal cancer syndrome, again autosomal dominant, which increases the risk of ovarian cancer by 12%. However, most women diagnosed with ovarian cancer have no family history and the etiology remains unknown. When ovarian cancer occurs and is not found early when it is located in an ovary, the cancer will usually spread first to the unaffected ovary and uterus, but can spread to the liver, lungs, adrenal glands, spleen, and other intraperitoneal organs.
Some things that reduce risk are the protective effects of oral contraceptives, late menarche, early menopause, multiparity (having more than one child), and breastfeeding. Progesterone appears to have a protective effect, but there is controversy as a 2009 Danish study suggests that all HRTs result in increased risk (study was done with estrogen alone (unopposed) or estrogen and progestin (progestin is a compound synthetic progesterone) Further studies on the use of natural bioidentical hormones for prevention will be needed to clarify this controversy, as previous studies have shown that HRT is protective There are modifiable factors such as weight loss (avoid obesity), quitting smoking, reduce high starch content, and A well-balanced diet rich in carotene, vitamins C and E, and unsaturated fats with moderate physical activity have been shown to help reduce the risk of ovarian cancer.
There is much difficulty in making an early diagnosis due to the fact that the signs and symptoms are very often subtle and non-specific, and unless you look for this disease with specific laboratory and radiology tests, you are not likely to find it soon enough. Some symptoms include abdominal pain and fullness, back pain, nausea, constipation, diarrhea, fatigue, pelvic pain, and urinary symptoms. Laboratory tests should be considered in women older than 40 years if these symptoms persist, as they are a population at higher risk for ovarian cancer. Testing generally involves a CBC, metabolic panel, and serum CA 125 levels. CA 125 is a cancer marker that is quite sensitive and specific for ovarian cancer; however, there are other conditions that can elevate this marker, such as pelvic inflammatory disease (PID), endometriosis, ovarian cysts, and pregnancy. CA 125 is a good but not perfect test, as it is elevated in 90% of patients with advanced disease, but only in more than 50% with stage I tumors. In addition, there are other markers that are becoming useful, including beta-subunit of human chorionic gonadotropin (Beta-HCG), serum alpha-fetoprotein (AFP), neuron-specific enolase (NSE), and lactate dehydrogenase (LDH). Diagnosis is also made using diagnostic imaging, such as transvaginal Doppler ultrasound (ultrasonography or ultrasonography), which is often used as the initial evaluation of a pelvic mass. Ultrasonography is useful in determining benign ovarian lesions, such as simple cysts, from those that appear more malignant, such as complex solid tumors. Other radiological imaging modes useful for diagnosis are computed tomography and gadolinium-enhanced magnetic resonance imaging.
Treatment generally includes (after extensive diagnostic testing and staging) surgical removal of the mass/tumor. Depending on the stage of the disease, other organs may also be removed, for example, the appendix is usually removed due to its potential metastatic target. After removal of the tumor, chemotherapy is usually started with a combination of platinum-based agents and taxanes. Carboplatin and taxol are two commonly used chemotherapy agents. For those women beyond their reproductive years, a total hysterectomy is often considered, while radiation therapy is reserved for palliative and persistent disease that recurs after a regiment of chemotherapy.
The prognosis is a bit complicated as it is based on the staging of the disease as well as the histological grade (type of tumor etiology) which usually plays a role in recurrence rates. For example, an epithelial ovarian cancer (histologically) has low malignant potential if diagnosed at stage I and has a 10-year survival rate of 95% to 99%.
Screening for ovarian cancer should include an annual physical exam and marker- and imaging-guided exams only when warranted. Routine screening with CA 125 produces too many false positives and misses too many tumors at first to be a good general screening test. BRCA testing should be reserved for descendants of those with mutated BRCA1 and BRCA2 genes, it is not recommended as a general screening tool. Current recommendations for women who meet criteria for high or very high risk of ovarian cancer is to have a transvaginal ultrasound and measure CA 125 every six months on days 1 to 10 of their menstrual cycle starting at age 35. years.
The take-home message here is that women should be diligent about their annual physicals and not ignore persistent symptoms that may point the finger at a more serious underlying condition.
References:
Roett, M. Evans, P., “Ovarian Cancer: An Overview,” American Family Physician, Vol. 80, Number 6, September 15, 2009, p.609-616.
www.ncbi.nlm.nih.gov/pubmed/10933270 (Accessed 10/8/2009)
www.medicinenet.com/script/main/art.asp?articlekey=103822 (Accessed 10/8/2009)
c) 2009