Clinical significance of cellular and acellular mucin pools in rectal carcinoma following preoperative chemoradiotherapy

Background and objectives: The standard treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (CRT) followed by surgery. Pathological findings remain the most significant prognostic factor. The presence of mucin pools and their prognostic significance is a controversial issue. The aim of this study was to analyze the incidence of cellular and acellular mucin pools and their clinical significance.

Methods: Four-hundred and forty-six consecutive prospectively collected specimens from patients with LARC treated with long-course preoperative CRT and surgery were analyzed. Kaplan-Meier analysis was performed.

Results: Mucin pools were present in 182 specimens (40.8 %); 66 (14.7 %) were acellular, and viable tumor cells were identified in 116 (26 %). The complete pathological response rate was 13.5 % (60 of 446). With a median follow-up of 79.0 months, the 5- and 10-year disease-free survivals for patients with acellular and cellular mucin pools were 81.5, 78.1, 63.7 and 61.2 %, respectively (p ≤ 0.026).

The presence of cells in the colloid response to treatment was associated with a 17.8 and 16.9 % decrease in 5- and 10-year disease survival vs. acellular colloid response.

Conclusions: Our results suggest that cellular mucin pools are an indicator of an aggressive phenotype and harbingers of a worse prognosis.

CITA DEL ARTÍCULO Clin Transl Oncol. 2016 Jul;18(7):714-21. doi: 10.1007/s12094-015-1422-8. Epub 2015 Oct 16