Colorectal cancer in patients less than 35 years: 10 year clinical experience from 3 University Hospital Trusts in South East London
Session type: Poster / e-Poster / Silent Theatre session
Colorectal cancer (CRC) incidence in patients younger than 50 and also younger than 35 has been rising globally and presents an emerging clinical challenge. Beyond recent large epidemiological publications, clinico-pathological datasets that characterise this patient group are lacking.
We reviewed all cases of CRC referred to 3 University Hospital Trusts in South East London from 2008 to 2018, with the aim of surveying the clinical and pathological landscape. Data was extracted from the Cancer treatment platform MOSAIQ and complemented by case note review. In total, 4460 new CRC patients were referred, of which 560 (12.6%) were younger than 50, and 111 (2.48%) younger than 35. The present work focused on the group younger than 35.
Patients ranged from 17 to 34 years, were predominantly male (59.5%) and Caucasian (69.4%), with Asians (9%) and Blacks (8.1%) in the minority. Location of primary tumour was mostly left-sided (66.7%; 81.6% in the Stage IV subgroup). Presenting stage was mainly III (50.5%) and IV (34.2%), II (19.8%) and I (0.9%). High rates of adverse histology were noted including poorly differentiated (22.5%), extramural vascular invasion (35.1%), mucinous (18%), and signet ring (7.2%). Low frequency of genetic predisposition was observed, 7.2% MSI-High/dMMR, 5.6% confirmed Lynch syndrome, and 2.7% FAP. Of 31 Stage IV patients, 42.1% had K/N-RAS and 5.3% BRAF mutations. In Stage III patients, median overall survival (mOS) was 7.35 years and median progression free survival (mPFS) 7.47 years. In Stage IV, mOS was 2.5 years and mPFS 0.67 years. In stage IV patients (n=38), resection of the primary tumour (n=17) versus not (n=21) was associated with significantly better mOS (not reached v 0.89 years, p=0003).
This study characterises a subgroup of CRC patients younger than 35 with adverse tumour biology, and lays a foundation for further improvements needed in prevention, early diagnosis, and therapy.