Feasibility of Wait and Watch Approach after Neoadjuvant Chemoradiotherapy in Rectal Cancer in Low- and Middle-Income Countries: Initial Experience in Tertiary Cancer Centre in India

Abstract

Wait and watch (W & W) approach after response to neoadjuvant chemoradiotherapy (NACRT) in locally advanced rectal cancer (LARC) is standard of care in medically inoperable patients. Otherwise, its use is recommended in a controlled research setting. In low- and middle-income countries (LMICs) there is presumed noncompliance with strict follow-up protocol of W & W approach due to geographical vastness, limited resources, and poor socioeconomic status. The objective of this study is to assess the feasibility, acceptance, and subsequent compliance to W & W approach after the clinical complete response (cCR) and near clinical complete response (ncCR) to NACRT in LARC. Patients diagnosed with LARC from September 2013 to January 2018 who had cCR and ncCR to NACRT (Radiotherapy dose 45-55 Gy) were offered either surgery as standard of care or W & W approach with strict follow up protocol consisting of regular digital rectal examination (DRE), magnetic resonance imaging (MRI) and sigmoidoscopy with informed consent. The cCR was defined as no palpable abnormality on DRE, white scar with telangiectasia on sigmoidoscopy and absence of residual tumor on T2W-MRI. The ncCR was defined as superficial soft irregularity or small flat ulcer at DRE, small residual flat ulcer or irregular wall thickening on the sigmoidoscopy and significant downstaging with/without residual fibrosis, but with a heterogeneous or irregular aspect on MRI. The first evaluation was done at 6-8 weeks after completion of NACRT and subsequently at 12 weeks. In this retrospective observational study, data was extracted from prospectively maintained rectal cancer database at our institution. All 28 patients (stage II = 14%, stage III = 86%) with cCR and ncCR preferentially opted for W & W approach over surgery. All 28 patients complied to a strict follow-up protocol of W & W approach. Median follow up was 47 weeks (Range 8 – 397 weeks). Eleven patients had cCR and 17 patients had ncCR after NACRT. All the 11 patients with cCR had no local regrowth, no regional or distant metastasis, or death. Five patients out of the total 17 patients in ncCR group developed cCR up to 1 year, 9 patients maintained ncCR, 1 patient developed regional and distant metastasis and died. Two patients underwent surgery due to the persistent ulcer at 21 weeks and 27 weeks after NACRT. Abdominoperineal resection was done for one patient and other underwent intersphincteric resection (ISR), both pT2 pN0 with TRG 2 and 3. Two patients had local regrowth, and one of them at 48 weeks underwent ISR. Other one had regrowth at 29 weeks and planned for surgery. In the entire cohort, organ preservation rate is 89.3%, local regrowth free rate (LRFR) is 89.3%, 2 Year PFS 82%, and 2 year OS is 91.7% using the Kaplan-Meier method. The W & W approach after cCR and ncCR to NACRT in LARC is acceptable with full compliance, feasible in LMICs in well-selected patients as a part of study group in a controlled research setting and early outcomes of this approach are similar to published literature.