Ovarian Cancer- Part 1

Introduction and types

Ovarian cancer is a cancer that originates in the ovaries or the surrounding tissues such as fallopian tubes or peritoneum. It is the 8th most common cancer in women worldwide and is predominantly observed in Europe. By 2050, the global burden of ovarian cancer is expected to increase by over 55% and mortality by almost 70%, highlighting the importance of raising disease awareness and promoting early detection among women to improve outcomes and ensure timely access to treatments.

Ovarian cancer is mainly of 3 types- epithelial ovarian tumours, germ cell tumours, and stromal tumors. Of these, epithelial ovarian tumours are the most common and account for 80-90% of cases. They start in the cells covering the outer surface of the ovary and include subtypes such as serous, endometrioid, clear cell, or mucinous carcinoma. Germ cell and stromal tumours are rare, and develop from germ cells (that produce eggs) or tissue cells that produce hormones, respectively. Ovarian tumours can be benign (non-cancerous), borderline (low malignant potential), or malignant (cancerous). The most common subtype of epithelial ovarian cancer is high-grade serous carcinoma, which is often diagnosed at an advanced stage.

Risk factors

Age, family history, and genetic mutations like BRCA1 and BRCA2 increase a women’s risk of developing ovarian cancer. Since BRCA1 and BRCA2 genes are critical in repairing damaged DNA, mutations impair this ability and cause accumulation of genetic errors, increasing cancer risk. Reproductive factors like late pregnancy/ infertility, early menarche and late menopause, hormone replacement therapy, and previous personal history of endometriosis, or breast/uterine/colorectal cancer are also associated with ovarian cancer. Hormone replacement therapy (HRT) for longer durations and of specific types increases oestrogen exposure, which can stimulate ovarian cell growth and hence ovarian cancer development.

Similarly, obesity increases the risk of disease occurrence and negatively impacts survival rates by multiple mechanisms. It contributes to the changes in the cellular and molecular composition of abdominal tissues and creates a pro-inflammatory environment that supports the survival of disseminating ovarian cancer cells. Moreover, obesity negatively affects the response to standard chemotherapy treatments and enhances metastatic success, underscoring the importance of maintain a healthy weight to reduce disease risk. Other non-lifestyle factors like smoking and alcohol consumption have also been linked to increased chances of developing ovarian cancer.

It's important to note that having one or more risk factors does not necessarily mean a woman will develop ovarian cancer. Conversely, many women who develop ovarian cancer have no known risk factors. Regular check-ups and discussing any concerns with a healthcare provider are essential for early detection and management of ovarian cancer risk.

Symptoms and diagnosis

Early-stage ovarian cancer rarely causes symptoms, making it challenging to detect. However, when noticeable, the symptoms include:

1)???? Swollen abdomen or constant bloating

2)???? Abdominal pain

3)???? Increased urination frequency or urgency

4)???? Difficulty eating or feeling full quickly

5)???? Changes in bowel habits

6)???? Unexplained weight loss

7)???? Back pain

8)???? Fatigue

Ovarian cancer is typically detected through a combination of diagnostic methods, as no single reliable screening test exists. A pelvic exam is often the starting point, during which a doctor examines the ovaries and surrounding organs for abnormalities. However, this method frequently fails to detect early-stage tumors. The CA125 blood test measures levels of the CA125 protein, which may be elevated in ovarian cancer, though it is not definitive since other conditions can also cause elevated levels. Ultrasound is commonly used as the initial imaging test to identify ovarian masses and distinguish between solid tumors and fluid-filled cysts. CT scans provide detailed cross-sectional images to assess cancer spread and guide biopsies, while MRI scans, though less commonly used, are helpful for examining specific areas, such as the brain and spinal cord, in cases of suspected metastasis. A biopsy, often performed during surgery, remains the only definitive way to diagnose ovarian cancer. Accurate diagnosis typically requires a combination of these tools to confirm the presence and extent of the disease.

Prevention

While ovarian cancer cannot be completely prevented, several strategies can help reduce its risk. Using birth control pills for at least five years has been shown to significantly lower the risk, with protective effects lasting for years after discontinuation. Reproductive choices, such as having children, especially before age 26, and breastfeeding, are associated with reduced risk due to fewer lifetime ovulations. Maintaining a healthy lifestyle by managing weight through a balanced diet and regular exercise is also crucial, as obesity is linked to increased cancer risk. Avoiding smoking is essential, as it is associated with certain ovarian cancer subtypes, and limiting alcohol consumption further supports overall health. For women with a family history of ovarian or breast cancer, genetic counselling and testing for mutations like BRCA1 and BRCA2 can help assess risk and guide preventive measures, including enhanced screening or preventive surgery. By adopting these approaches and consulting healthcare providers, women can take proactive steps to lower their risk and promote better health outcomes.

Staying informed and proactive about one’s health can also make a significant difference. Regular gynaecological check-ups allow for the monitoring of any unusual symptoms, such as persistent bloating, pelvic pain, or changes in appetite, which may indicate early warning signs. For women with a strong family history of ovarian or breast cancer, preventive surgeries, such as risk-reducing salpingo-oophorectomy, can drastically reduce the likelihood of developing ovarian cancer. Additionally, adopting a nutrient-dense diet rich in fruits, vegetables, and omega-3 fatty acids, while avoiding processed foods, may offer added protection. Public health campaigns and awareness programs play a critical role in educating women about ovarian cancer and encouraging early interventions, empowering them to make informed decisions about their health.

Conclusion

To conclude this first part of the blog, ovarian cancer remains a significant global health challenge often due to its late detection and rising incidence rates. Understanding the types of ovarian cancer, recognizing risk factors, and being vigilant about symptoms are crucial steps toward improving early detection and treatment outcomes. While the disease cannot be entirely prevented, adopting healthy lifestyle habits, considering risk-reducing strategies, and staying informed about available diagnostic tools can empower women to take control of their health. Public awareness and education play an indispensable role in equipping women with the knowledge needed to identify early warning signs and seek timely medical attention. Together, these efforts can pave the way for better outcomes and a reduced burden of ovarian cancer worldwide.

References

Huang, J., Chan, W. C., Ngai, C. H., Lok, V., Zhang, L., Lucero-Prisno, D. E., 3rd, Xu, W., Zheng, Z. J., Elcarte, E., Withers, M., Wong, M. C. S., & On Behalf Of Ncd Global Health Research Group Of Association Of Pacific Rim Universities Apru (2022). Worldwide Burden, Risk Factors, and Temporal Trends of Ovarian Cancer: A Global Study.?Cancers,?14(9), 2230. https://doi.org/10.3390/cancers14092230

Liu, Y., Yang, J., Hilliard, T.S.?et al.?Host obesity alters the ovarian tumor immune microenvironment and impacts response to standard of care chemotherapy.?J Exp Clin Cancer Res?42, 165 (2023). https://doi.org/10.1186/s13046-023-02740-y

Pan, Z., & Xie, X. (2017). BRCA mutations in the manifestation and treatment of ovarian cancer.?Oncotarget,?8(57), 97657–97670. https://doi.org/10.18632/oncotarget.18280

Shea, A. A., Heffron, C. L., Grieco, J. P., Roberts, P. C., & Schmelz, E. M. (2024). Obesity modulates the cellular and molecular microenvironment in the peritoneal cavity: implication for ovarian cancer risk.?Frontiers in Immunology,?14, 1323399. https://doi.org/10.3389/fimmu.2023.1323399

Xiang, H., Wang, L., Sun, L., & Xu, S. (2024). The risk of ovarian cancer in hormone replacement therapy users: a systematic review and meta-analysis.?Frontiers in Endocrinology,?15, 1414968. https://doi.org/10.3389/fendo.2024.1414968

Cancer Research UK. Types of ovarian cancer. https://www.cancerresearchuk.org/about-cancer/ovarian-cancer/types

American Cancer Society. What is Ovarian Cancer. https://www.cancer.org/cancer/types/ovarian-cancer/about/what-is-ovarian-cancer.html

World Cancer Research Fund. Ovarian Cancer Statistics. https://www.wcrf.org/preventing-cancer/cancer-statistics/ovarian-cancer-statistics/

World Ovarian Cancer Coalition. Ovarian Cancer Key Stats. https://worldovariancancercoalition.org/about-ovarian-cancer/key-stats/

CDC. Ovarian Cancer Risk Factors. https://www.cdc.gov/ovarian-cancer/risk-factors/index.html

NHS. Ovarian Cancer. https://www.nhs.uk/conditions/ovarian-cancer/symptoms/

Memorial Sloan Kettering Cancer Center. Ovarian Cancer Risk Factors & Prevention. https://www.mskcc.org/cancer-care/types/ovarian/risk-prevention

Ovarian Cancer Action. Ovarian Cancer Prevention. https://ovarian.org.uk/ovarian-cancer/ovarian-cancer-prevention/

Mayo Clinic. Ovarian Cancer Detection. https://www.mayoclinic.org/diseases-conditions/ovarian-cancer/diagnosis-treatment/drc-20375946

American Cancer Society. Tests for Ovarian Cancer. https://www.cancer.org/cancer/types/ovarian-cancer/detection-diagnosis-staging/how-diagnosed.html