8.DEC.2016 6 MIN READ | 6 MIN READ

Ovarian cancer has been dubbed a silent killer as it often presents at a late stage, resulting in low survival rates.

Dr Elisa Koh, obstetrician and gynaecologist at Mount Elizabeth Novena Hospital explains the current statistics and treatment methods for ovarian cancer.

With ovarian cancer, there is no effective screening method, nor are there feasible protocols for early detection even in high risk individuals. Symptoms are often vague and non-specific, and require awareness on the part of the woman as well as the primary physician. Ovarian cancer is on the rise in Singapore, and may well become the top gynaecological cancer in the near future.

Current statistics

A review of the Singapore Cancer Statistics of the incidence of ovarian cancer reveals an alarming trend. In the 1970s, cervical cancer was the 3rd most common cancer in women, while ovarian cancer ranked at number 7. Ovarian cancer inched up slowly over the next decade to become the 6th most common cancer, and the turning point came in late 1990s when it overtook cervical cancer to take the 4th spot while cervical cancer dropped to the 5th.

In the latest interim report for 2010 – 2015, it holds steady at the 5th position while cervical cancer has dropped to the 10th spot.

Common symptoms of ovarian cancer

Ovarian cancer is known to have an insidious onset. Patients only start showing symptoms in the late stages when there is gross distension of the abdomen due to the presence of an ovarian mass, or gross ascites. The symptoms of ovarian cancer are unfortunately non-specific, and they may include:

  • Distension from pelvic mass and/or ascites
  • Bloating
  • Pelvic and/or abdominal pain
  • Increased urinary frequency or urgency
  • Unexplained weight loss
  • Changes in bowel habits

The Ministry of Health (MOH) released a screening guideline in 2010 stating that multimodal screening women with average risk for ovarian cancer is not recommended as there are no effective methods for the routine screening of these asymptomatic women. However, the guideline mentions that, for women at increased risk (women with a positive family history or hereditary syndromes), there is insufficient evidence for or against screening, and any form of screening method would be based on expert consensus only.

Management of ovarian cancer

Ovarian cancer is still essentially managed and staged surgically. Primary debulking surgery to remove as much of the disease as possible, followed by platinum-based chemotherapy is regarded the gold standard of treatment.

For patients with advanced disease which has spread, for whom surgery may be suboptimal, a few cycles of chemotherapy can be considered before surgery. This downsizes the disease load, allowing for a better nutritional status and more operable disease at time of surgery. With good imaging techniques now available, operability can now be more reliably assessed at time of presentation, and options discussed with the patient. Such management has been shown to have equal survival outcomes as the traditional management of primary surgery followed by adjuvant chemotherapy.

Targeted therapy is now being extensively studied and combined with conventional chemotherapy. Combination therapy has also been shown to be useful in combating recurrent disease, prolonging the progression-free survival as well. Immunotherapy is also being extensively studied. Experimental tumour vaccine therapy based on cancer antigens have also been tested in ovarian cancer patients, with such treatment aimed at inducing T-cell responses.

Ovarian cancer is currently the most deadly gynaecological cancer and is on the rise. Till an effective screening method can be identified, the focus for the future will evolve around meticulous and timely surgery, effective chemotherapy and novel therapeutics, such as biologic and targeted therapies. 

References

1. Ferraro S et al. Serum Human Epididymis Protein 4 vs Carbohydrate Antigen 125 for ovarian cancer diagnosis. A systematic review. J Clin Pathol 2013;66(4):273-81.

2. Gorp TV et al. HE 4 and CA 125 as a diagnostic testin ovarian cancer: prospective validation of the Risk of Ovarian Cancer Algorithm. Br J Cancer 2011;104(5):863-70

3. Campbell S, Bhan V, Royston J et al. Screening for early ovarian cancer. Br J Obstet Gynaecol 1986;93:1286-9

4. van Nagell JR et al. Ovarian cancer screening with annual transvaginal sonography: findings of 25,000 women screened. Cancer 2007;109(9):1887-96.

5. Skates SJ, Xu FJ, Yu YH et al. Toward an optimal algorithm for ovarian cancer: a pilot randomised controlled trial. Cancer 1995; 76:Suppl:2004-10

6. Jacobs IJ et al. Ovarian cancer screening and mortality in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS): A randomised controlled trial. Lancet 2016;387:945-56.

7. Vergote I et al. Neoadjuvant chemotherapy or primary surgery in Stage IIIC or IV Ovarian Cancer. N Engl J Med 2010;363:943-53.

8. Aghajanian C et al. OCEANS: A randomized, double-blind, placebo-controlled Phase III Trial of chemotherapy with or without bevacizumab in patients with platinum-sensitive recurrent epithelial ovarian, primary peritoneal or fallopian tube cancer. J Clin Oncol 2012;30:2039-45.

9. Perren TJ et al. A Phase 3 Trial of Bevacizumab in Ovarian Cancer. N Engl J Med 2011;365:2484-96. 

10. Disis ML et al. Effect pf dose on immune response in patients vaccinated with an ER-2/neu intracellular domain protein-based vaccine. J Clin Oncol 2004;22:1916-1925.

8.DEC.2016
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Koh Poh Kim, Elisa
Obstetrician & Gynaecologist
Mount Elizabeth Hospital

Dr Elisa Koh is an obstetrician and gynaecologist practising at Mount Elizabeth Novena Hospital, Singapore. Apart from delivering babies, Dr Koh has special interests in the prevention and management of gynaecological cancers.

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