Cancellation or delays of chemotherapy protocols are
common in cancer patients and might adversely affect
prognosis. Associations between non-adherence to chemotherapy
protocols or reduction in dose intensity in the
adjuvant setting were shown to impact disease control or
decrease survival for colorectal cancer,1e4 breast cancer5,6
and small-cell lung cancer.7
Infections constitute an important reason for nonadherence
to chemotherapy protocols. Of all infections,
influenza and other viral respiratory infections are the most
preventable through vaccination or other prevention measures.
Previous studies have focused mainly on cytopenias
and mucositis as causes of chemotherapy rejections.1e7 The
association between viral respiratory infections and chemotherapy
delays has not been previously assessed to our
knowledge. Quantification of this association might help
direct prevention efforts. In the current study we aimed
to examine the reasons and risk factors for interruption
(delay or cancellation) of planned chemotherapy in a
cohort of cancer patients, focusing on the relative contribution
of influenza and influenza-like illness.