Surgical upstaging rates in patients meeting the eligibility for active surveillance trials.

Purpose: Four clinical active surveillance trials including LORIS, COMET, LORD and LORETTA, are being conducted to assess whether women with low-risk ductal carcinoma in situ can safely avoid surgery. The present study aimed to determine the rate of upstaging to invasive cancer among patients with a preoperative diagnosis of ductal carcinoma in situ and to evaluate the incidence of upstaging in patients meeting the eligibility criteria for four active surveillance clinical trials.

Methods: The present study initially enrolled 180 patients with 183 calcifications who received the diagnosis of ductal carcinoma in situ by biopsy. Patients were classified as eligible for four clinical trials according to the respective inclusion criteria.

Results: In total, 152 patients with 155 calcifications were analyzed. Of these, 32 (21%) were upstaged to invasive disease based on the final pathological analysis of surgical specimens. Of the 152 patients, 53 (35%), 90 (59%), 24 (16%) and 34 (22%) met the eligibility criteria for the LORIS, COMET, LORD and LORETTA trial, respectively. Among patients with low-risk ductal carcinoma in situ, 10 (19%), 14 (16%), 6 (25%) and 4 (12%) patients were upstaged to invasive disease in LORIS, COMET, LORD and LORETTA, respectively. The upstaging to pT1b or higher rates were 2% (1/53), 3% (3/90), 0% (0/24) and 3% (1/34) in LORIS, COMET, LORD and LORETTA, respectively.

Conclusions: The upstaging rate in patients eligible for the clinical active surveillance trials was 12-25%. Although the rate of upstaging to pT1b or higher was low, further studies are required to determine the rates of upstaging to invasive cancer and the risk factors among patients with low-risk ductal carcinoma in situ.