Squamous cell carcinoma of the rectum: The treatment paradigm D. Musio a, * , F. De Felice a , S. Manfrida b , M. Balducci b , E. Meldolesi b , G.L. Gravina c , V. Tombolini a , V. Valentini b a Department of Radiotherapy, University of Rome “Sapienza”, Viale del Policlinico 155, 00161, Rome, Italy b Department of Radiotherapy, Universita Cattolica del Sacro Cuore, Largo A. Gemelli 8, 00168, Rome, Italy c Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy Accepted 30 March 2015 Available online 24 April 2015 Abstract Purpose: This study was planned to clarify the optimal treatment for squamous cell carcinoma of the rectum, an histological entity extremely rare. Methods: Ten patients with histologically proven squamous cell carcinoma of the rectum were treated with concomitant radiochemotherapy. Radiation therapy was delivered with a 3Dconformational multiple field technique to a dose ranging from 45 to 76.5 Gy, with 6e15 MV energy photons. Chemotherapy consisted of an antimetabolite drug in association with mitomycin C or oxaliplatin. Overall survival and disease free survival were considered in months from the end of the concomitant treatment. Results: All patients completed programmed radiochemotherapy treatment but two patients were excluded to the analysis. Six patients (75%) presented negative biopsy 6 months after the end of radiochemotherapy. Seven patients (87.5%) showed a tumour regression after initial treatment. Only 1 patient underwent salvage surgery. Considering a mean follow-up of 41.75 months, 7 patients are still disease free survivors. Only 1 patient developed local recurrence at 6 months and he died 14 months after abdomino-perineal resection. Conclusion: Primary radio chemotherapy, with a curative intent, could be considered the treatment modality of choice for squamous car- cinoma of the rectum. Ó 2015 Elsevier Ltd. All rights reserved. Keywords: Squamous cell carcinoma; Rectal cancer; Radiotherapy; Radiochemotherapy Introduction The majority of rectal cancer is adenocarcinomas; other histologic type are rare and include carcinoid tumours, lym- phomas, leiomyosarcomas and squamous cell cancers. Squamous cell carcinoma is an unusual condition: it repre- sents 0.1e0.25 per 1000 cases of colorectal cancers. 1,2 Given the rarity of this disease, strong data, regarding epidemiology, pathogenesis and optimal therapy, is lacking. Although some authors are not sure it exists, 3 over the years, four hypotheses have developed to explain the phys- iopathology of squamous cell carcinoma of the rectum: 1) squamous metaplasia resulting from inflammation or irritation secondary to infection, 4,5 radiation 6 or in- flammatory bowel disease 7e9 ; 2) possibility of pluripotent stem cells capable of squa- mous differentiation 10,11 ; 3) malignant transformation of epithelial damage 12 ; 4) malignant transformation of preexisting adenomas. 13 Diagnostic criteria for squamous cell carcinoma of the rectum were established by Williams et al. 14 and included: absence of any anal canal extension, absence of fistulous tract, absence of evidence of metastasis. Because the low incidence of the disease, only case reports 4,6,9,12,13,15,16,21e27 and small case series 2,10,17e20,32 have been reported in literature, since Rainford, 15 in 1933, had described the first case of squamous cell * Corresponding author. Tel.: þ39 0649973411, þ39 3403319229 (mobile). E-mail address: daniela.musio@libero.it (D. Musio). http://dx.doi.org/10.1016/j.ejso.2015.03.239 0748-7983/Ó 2015 Elsevier Ltd. All rights reserved. Available online at www.sciencedirect.com ScienceDirect EJSO 41 (2015) 1054e1058 www.ejso.com