To study the impact of time factors on local and distant metastases in stomach cancer. 67 patients with gastric cancer who received adjuvant treatment were reviewed for the time to initiation of radiotherapy, overall duration of RT and the events of first local recurrence or distant metastasis. The risk probability of local recurrence is increased by 10% (HR=1.1, p=0.0009) in association with each additional day of radiotherapy and by 3.8% (HR=1.038, p=0.13) per increased day of waiting time before the initiation of RT. The risk probability of distant recurrence was associated with an increase of 7.4% (HR=1.074 p=0.0031) with each additional day of RT time and by 2.3% (HR=1.023, p=0.0598) following the increase of a day of waiting time. Each day of prolongation of RT beyond 36 days was associated with an increased risk of local recurrence by 10% (OR=1.1, p=0.015). Prolongation of waiting time prior to initiation of irradiation retained significance in multivariate analysis. There is an association between total treatment time and, to some extent, the time between the surgery and the initiation of radiation on local control and distant metastases.

Background and Aim: The BNT162b2 COVID‐19 vaccine (Pfizer/BioNTech), given as a two‐dose series, 3 weeks apart, elicits a serological response in 84–98% of patients with cancer, even if administered while undergoing anticancer treatments. Herein, we report the impact of a third (booster) dose of BNT162b2, delivered 6 months following the second vaccine dose.Methods: This pilot study included four patients with cancer who were seronegative after two vaccine doses, and received a third (booster) dose of BNT162b2 at 6 months following the second vaccine dose. The four patients received the three vaccine doses between December 2020 and July 2021. Samples were evaluated with an enzyme‐linked immunosorbent assay (ELISA) that detects IgG (Immunoglobulin G) antibodies against the RBD (receptor‐binding domain) of SARS‐CoV‐2.Results: At a mean time of 19 days (ranges 7–28) after the second vaccination, all four patients were seronegative for RBD‐IgG. However, at a mean time of 21 days (ranges 20–22) after the third dose, three out of the four patients (75%) were now seropositive. Mean RBD‐IgG titers were increased after the third vaccine dose from 0.37 to 2.81 (Student's t‐test, p = 0.05, two‐sided).Conclusions: Although limited by the small sample size, our findings suggest that a third (booster) dose administered to patients with cancer, who remain seronegative despite two doses of BNT162b2, may be efficacious in eliciting an antibody response.