Further Readings^{4, 9}

Natural History and Risk Factors of Ovarian Cancer

• Early diagnosis of ovarian cancer can be challenging as early-stage ovarian cancer is mostly asymptomatic,¹⁰ but when presented with symptoms (e.g. pelvic or abdominal pain, increased abdominal size or bloating, difficulty eating or feeling full, urinary urgency or frequency), they are non-specific.⁴ Education on risk factors (S Table 1.) and clinical features of ovarian cancer is essential to encourage women to seek medical attention and facilitate early diagnosis through timely investigation and management of ovarian cancer.

Effectiveness of Ovarian Cancer Screening

• Currently, international guidelines do not recommend ovarian cancer screening for asymptomatic women at average risk, as such screening has not demonstrated a mortality benefit. Large randomized controlled trials, including the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), have shown no significant reduction in ovarian cancer mortality among post-menopausal women screened with CA-125, transvaginal ultrasound (TVUS), or a combination of both.^{2, 3}
• Research on the effectiveness of ovarian cancer screening for local women at increased risk is lacking. Internationally, there is limited data on the effectiveness of ovarian cancer screening and mortality reduction for women with a family history of ovarian or breast cancer, or genetic mutations such as BRCA1 or BRCA2. Phase I of the United Kingdom Familial Ovarian Cancer Screening Study (UK FOCSS) found that annual screening with CA-125 and transvaginal ultrasound (TVUS) did not significantly change the stage at diagnosis. However, Phase II showed that combining CA-125 screening with the Risk of Ovarian Cancer Algorithm (ROCA) every four months, along with TVUS as determined by ROCA, resulted in a significant stage shift. The impact of ROCA-based screening on survival improvement and the implications of this stage shifting remains unknown.^{5, 6}
• Potential harms of ovarian cancer screening include psychological morbidity, false-positive results and subsequent invasive surgeries. Women who underwent recall screening and follow-up investigations had a significantly increased risk of psychological morbidity (OR = 1.28, 95% CI 1.18-1.39).¹¹