Effectiveness of triennial screening with clinical breast examination: 14-years follow-up outcomes of randomized clinical trial in Trivandrum, India

Abstract

Background: This study presents the preliminary results of a randomized controlled trial (RCT) initiated in January 2006 in India to evaluate the effectiveness of clinical breast examination (CBE) in reducing breast cancer mortality as compared to a no-screening control group reported significant downstaging in the intervention group. The present manuscript reports long-term follow-up outcomes. Methods: Women 30–69 years old from 133 intervention clusters and 141 control clusters were invited to participate. Women in the intervention arm underwent three rounds of CBE every 3 years. CBE-positive women were reexamined by a physician, and triple-assessment was performed on those confirmed to have abnormalities. All participants were followed through home visits and linkage with population-based cancer registry. Results: Of the 55,843 eligible women in the intervention arm, 95.7% had CBE at least once and 11.5% were CBE-positive. Breast cancers were diagnosed in 335 participants in the intervention group and 273 in the control group (N = 59,447). Age-standardized incidence rate of early cancer was 30.4 of 100,000 in the intervention and 21.9 of 100,000 in the control group, with a rate ratio (RR) of 1.4 (95% confidence interval [CI], 1.1–1.8). The age-standardized breast cancer mortality rates were 11.3 and 11.1 per 100,000 in intervention and control arms, respectively (RR, 1.1; 95% CI, 0.8–1.5) after 15 years. Five-year breast cancer survival rates were 77.0% in the intervention and 71.2% in the control groups (overall p value =.043). Conclusions: Triennial CBE screening failed to demonstrate any mortality benefit despite achieving a shift toward earlier stage at detection and improved survival in the intervention arm. CBE is a valuable tool for diagnosis of breast cancer in symptomatic women especially in areas where mammography and/or breast cancer screening programs are not widely available.