Ovarian cancer risk factors by tumor dominance, a surrogate for cell of origin.

Jan 2013

Kotsopoulos J, Terry KL, Poole EM, Rosner B, Murphy MA, Hecht JL, Crum CP, Missmer S, Cramer DW, Tworoger SS.

Source

Women's College Research Institute, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.

Abstract

Differentiating ovarian tumors based on developmental pathway may further our understanding of the disease. Traditionally,ovarian cancers were thought to arise from the ovarian surface epithelium; however, recent evidence suggests some tumors originate in the fallopian tube. We classified cases in a population-based case-control study (NECC) and two cohort studies (NHS/NHSII) by tumor dominance, a proxy for tissue of origin. Dominant tumors (likely ovarian origin) are restricted to one ovary or are at least twice as large on one ovary compared to the other. Ovarian cancer risk factors were evaluated in relation to dominant and non-dominant tumors (likely tubal origin) using polytomous logistic regression (NECC) or competing risks Cox models (NHS/NHSII). Results were combined using random-effects meta-analyses. Among 1,771 invasive epithelialovarian cancer cases, we observed 1,089 tumors with a dominant mass and 682 with no dominant mass. Dominant tumors were more likely to be mucinous, endometrioid, or clear cell, whereas non-dominant tumors were more likely to be serous. Tubal ligation, two or more births, endometriosis, and age were more strongly associated with dominant (RRs = 0.60, 0.83, 1.58, 1.37, respectively) than non-dominant tumors (RRs = 1.03, 0.93, 0.84, 1.14 p-difference = 0.0001, 0.01, 0.0003, 0.01, respectively). These data suggest that risk factors for tumors putatively arising from ovarian versus fallopian tube sites may differ; in particular, reproductive factors may be more important for ovarian-derived tumors. As this is the first study to evaluate ovarian cancer risk factors by tumor dominance, these results need to be validated by other studies.

PubMed

What is ovarian cancer and how can you fight it?

What is ovarian cancer and how can you fight it?

According to a study conducted by the World Health Organisation, one in every 12 women in urban India will, potentially, suffer from cancer. 

The five main types of cancer that can affect a woman's organs are cervical, ovarian, uterine, vaginal and vulvar. Among these, breast cancer is a leading cause behind the maximum number of cancer-related female deaths in India, closely followed by ovarian cancer.Ovarian cancer is more dangerous than any other cancers because the survival rate of a woman suffering from ovarian cancer is far lower than any other cancer that affects women, as it is difficult to detect in the early stages. Today, we take a look at this slow killer and tell you how you can prevent it. 

What is ovarian cancer? 

According to ovariancancer.org, 'Ovarian cancer is a growth of abnormal malignant cells that begins in the ovaries.'

Ovarian cancer can be of two types: Benign (non-cancerous) and malignant (cancerous).

The only difference between the two is that in its benign form, the tumors do notspread to the other parts of the body; whereas in its malignant form, the tumor spreads to other parts of the body through the bloodstream. 

What are its symptoms? 

Early stages may not show many symptoms, but as the cancer grows there may be symptoms like:-

Pain in the abdomen, pelvis or legs

Swollen abdomen

Nausea, diarrhea or constipation

Feeling tired all the time

Difficulty in eating 

Weight loss or weight gain

Fatigue

Pain during intercourse

Frequent urination

The above symptoms are very common and may be associated with normal health worries, but if the problem persists over a longer duration, take medical assistance quickly as negligence may prove fatal. 

Is ovarian cancer treatable? 

Ovarian cancer is treatable, if detected in the early stages. If diagnosed at the right time, medical treatment can prevent the tumor/s from spreading to different parts of the body.

Depending on the stages of the cancer, your doctor may suggest a combination of treatments. Mostly a surgery is carried out, followed by chemotherapy. The various treatments are as follows. 

Surgery 

A surgery is carried out, both to diagnose ovarian cancer and to treat it as well. Tissue is removed from the ovary to examine it. Once examined, the main goal of the surgeon is to remove the tumor completely. To prevent the spreading of the tumor, your doctor may remove ovaries and the surrounding tissues. A second surgery may also be carried out after all other treatments. 

Chemotherapy 

This treatment uses drugs to slow down the growth of cancer and reduce the chances of reoccurrence. 

Radiation therapy 

Women with ovarian cancer are mostly treated with external radiation. The treatment uses a high energy X-ray to kill all the cancer causing cells. 

Risks factors 

The fact is that ALL women, are at a risk of developing ovarian cancer, simply because they are women. Therefore all women's should check the signs and prevent it from happening. Besides this, some other risk factors are 

Family history 

According to the American Cancer Society, 10% of ovarian cancer can be hereditary. Having a family history of ovarian, breast or colorectal cancer increases the chances of ovarian cancer in women. The possibility of developing ovarian cancer is due to the mutations in BRCA1 or BRCA2 genes. The younger you are or the family member who got diagnosed with the disease, the higher are your chances of developing ovarian cancer. 

Post menopausal 

Most of the ovarian cancer cases have been diagnosed in women who have crossed the age of 55-60 or after a women has entered menopause. 

Overweight 

According to Dr. Sheetal, there is a high chance of developing ovarian cancer if you are obese. The American Cancer Society has also correlated a higher rate of ovarian cancer in obese women. 

Infertility 

Women who have never been pregnant or have used some sort of drugs to achieve pregnancy seem to have a higher risk of developing ovarian cancer. 

What can one do to prevent ovarian cancer? 

The appropriate medicine has still not been discovered, but here are a few tips to reduce one's risk of developing ovarian cancer. 

Oral contraception 

Consumption of birth control pills for more than 5 years can reduce the risk of developing ovarian cancer. The longer the birth controls pills are used, the lesser are the chances of developing ovarian cancer. However, you must consult your doctor before assuming that the pills you take will prevent ovarian cancer, especially if you take them regularly. 

Breastfeeding and pregnancy 

Bearing children before the age of 28 can reduce the risk of ovarian cancer. Breastfeeding may also decrease one's risk of developing ovarian cancer. 
Surgical prevention 

Women who are at a higher risk of developing ovarian cancer due to genetics or who are outside of their reproductive stages can opt for surgical preventions. The various surgical preventions such as tubal ligation and oophorectomy can greatly reduce the risk of developing ovarian cancer.Read more Personal Health, Diet & Fitness stories on www.healthmeup.com