Background: Personal financial payments from the pharmaceutical industry to oncologists are common and increasing. A prevalent view is that the purpose of industry payments to physicians is to facilitate education on new drugs. However, little is known regarding the distribution and trends in industry payments related to cancer drugs. The goal of this study was to characterize current patterns in industry payments related to cancer drugs, and test whether these patterns are consistent with an educational purpose. Methods: We included on-patent cancer drugs without generic/biosimilar competitors, and used publicly-available federal data sources to measure Medicare spending (proxy for overall drug revenue), number of prescribers, and industry payments (Open Payments, which includes data regarding which the drug[s] was the subject of each payment) for each calendar year from 2014-2018. We analyzed General Payments to individual physicians, which encompasses payment types such as meals, travel, consulting, and speaking fees. We tested two hypotheses implied by the claim that industry payments serve educational purposes. First, payment amounts should not be associated with drug revenue. To test this hypothesis, we used generalized estimating equations (GEE) to model the association between mean per-physician industry payments and Medicare spending. Second, payments related to a given drug should decline over time as physicians become educated. To test this hypothesis, we determined the relative year-to-year change in industry payments for all cases wherein consecutive years were observed, and used GEE to estimate the year-to-year change with respect to duration of time since initial FDA approval. Results: The sample included 89 drugs and 361 drug-year observations. The total amount of industry payments for oncology drugs increased during the study period, from $53,333,854 in 2014 to $90,343,731 in 2018. There was no association between log-transformed mean, per-physician industry payments and per-physician Medicare spending (estimate -0.001, 95%CI: -0.005, 0.004). In aggregate, Industry payments for cancer drugs were greatest immediately after FDA approval and trended downward over time; the estimated industry payments in the subsequent year for a drug with mean payments of $1,000 per-physician in the index year was: $681* for drugs 0-4 years since approval, $825 for drugs 5-9 years, and $679* for drugs≥10 years (*p<0.05). Conclusions: The absence of association between industry payments and Medicare spending and the decline in industry payments for drug subsequent to approval are consistent with claims that these payments function to facilitate physician education.