Could diagnostic and therapeutic delay affect the prognosis of gastrointestinal primary malignancies in the COVID-19 pandemic era? A literature review.

BACKGROUND Emergency situations, as the Covid-19 pandemic that is striking the world nowadays, stress the national health systems which are forced to rapidly reorganizing their sources. Therefore, many elective diagnostic and surgical procedures are being suspended or significantly delayed. Moreover, patients might find it difficult to refer to physicians and delay the diagnostic and even the therapeutic procedures because of emotional or logistic problems. The effect of diagnostic and therapeutic delay on survival in patients affected by gastrointestinal malignancies is still unclear. METHODS We carried out a review of the available literature, in order to determine whether the delay in performing diagnosis and curative-intent surgical procedures affects the oncological outcomes in patients with oesophageal, gastric, colorectal cancers, and colorectal liver metastasis. RESULTS The findings indicate that for oesophageal, gastric and colon cancers delaying surgery up to 2 months after the end of the staging process does not worsen the oncological outcomes. Oesophageal cancer should undergo surgery within 7-8 weeks after the end of neoadjuvant chemoradiation. Rectal cancers should undergo surgery within 31 days after the diagnostic process and within 12 weeks after neoadjuvant therapy. Adjuvant therapy should start within 4 weeks after surgery, especially in gastric cancer; a delay up to 42 days may be allowed for oesophageal cancer undergoing adjuvant radiotherapy. CONCLUSIONS Gastrointestinal malignancies can be safely managed taking into account that reasonable delays of planned treatments appear a generally safe approach, not having a significant impact on long-term oncological outcome.