To our knowledge, this is the first study to investigate the outcomes of curative and palliative anticancer treatments during the COVID-19 pandemic. The data were collected from large comprehensive cancer centers to support the assumption of the risks of mortality and morbidity associated with anticancer treatments during pandemics.
Our population-based study demonstrated that the 30-day mortality for all patients who received anticancer treatments was 5.1%, of which 1.8% accounted for curative intent, 8.6% for palliative intent, and 13.4% for COVID-19-positive cases. The 30-day mortality rate of 5.1% in this study could be established as a benchmark at the national level and is comparable to those reported in Australia, England, and New Zealand (5.6%, 4%, and 5.17%, respectively) (16),(17),(18),(19). For curative and palliative intent, we examined all patients with different cancers—unlike other studies that focused only on certain types of tumors, such as the Systemic Anti-Cancer Therapy Dataset collated by Public Health England, which reported 30-day mortality rates of 3% and 10% for curative and palliative chemotherapy, respectively, for patients with lung cancer. For breast cancer, the 30-day mortality rates were 1% and 7% for curative and palliative chemotherapy, respectively (20). Moreover, the Royal Marsden Hospital reported 30-day mortality rates of 0.5% and 1.5% for curative chemotherapy in breast cancers and for curative chemotherapy in GI malignancies, respectively (21).
Our study highlights that important subgroups may be at higher risk of mortality, such as male patients, those with BMI < 25, and those receiving hormone therapy. The number of cycles also significantly increased the risk of mortality. We also found that ECOG-PS 0–1, cancer stages I and II, and curative intent significantly decreased the mortality risk. For COVID-19 cases, similar to the results of the TERAVOLT registry (22), our study showed that receiving chemotherapy was associated with an increased mortality risk. However, the patients enrolled in the TERAVOLT registry were older, had lung cancer only, and were COVID-19 positive, unlike in our study where we included patients regardless of the cancer type and the majority of them were aged < 65 years. Again, similar to data from the CCC19 database (23), being male and having an ECOG-PS of ≥ 2 in this study were associated with increased 30-day mortality. Our study included all patients on active anticancer treatments, in contrast to the CCC19 database where only 39% of patients were on active anticancer treatment. Our observed mortality rate for COVID-19 was 13.4%, which is comparable to that reported in China (14%) (24), the CCC19 database (13%) (23), and the Mount Sinai Health System (11%) (25). However, contrary to international reports, we had a lower incidence of COVID-19 in our cohort, and this needs to be explored in future studies.
So far, no studies have described the 30-day morbidity associated with all types of anticancer treatments. Our study results showed that the 30-day morbidity was 28.2% for all patients receiving anticancer treatments, of which 17.9% accounted for curative intent, 39.3% for palliative intent, and 75% for COVID-19 cases. The factors significantly associated with an increased risk of morbidity were age > 65 years, BMI < 25, chemotherapy, hormone therapy, and immunotherapy. We also found that a significant decrease in morbidity was associated with an ECOG-PS of 0–1, breast cancer, urologic cancer, and curative intent of treatment. The significant increase in the 30-day morbidity of anticancer treatments suggests that oncologists should carefully consider selecting the best regimen, dose, schedule, route, and follow-up for patients receiving anticancer treatments. This must be coupled with an appropriate healthcare system and quality indicators to identify patients who need continuous support (e.g., day care, home care visit, or telemedicine), along with supportive medications to avoid potential harm.
This study has several strengths. First, we described the 30-day mortality and morbidity of curative and palliative anticancer treatments in the outpatient setting during the COVID-19 pandemic, which have not been reported previously. Second, our population was diverse in terms of age distribution, stage and type of cancer, curative and palliative intent, and presence of solid versus hematological malignancies. Lastly, we included all types of anticancer treatments such as chemotherapy, immunotherapy, targeted therapy, and hormone therapy as well as the most common routes of treatment such as IV, SC, and oral. However, there are limitations to be considered. First, the study has a retrospective design. Second, the study was restricted to Saudi Arabia, which limits the inferences that can be drawn from the findings. Third, the majority of patients were younger than 65 years and were females with breast cancer. However, we attempted to control for these factors by inviting more centers to participate, which could yield a real difference in findings between our study and those of others. Finally, there was a lower incidence of COVID-19 cases in our cohort, which might be related to patients having no or mild symptoms. Prospective cancer registries for COVID-19 cases can capture more accurate data, which would be a possible avenue for future research.
In conclusion, our findings add to previous knowledge on the outcomes of curative and palliative anticancer treatments for solid and hematological malignancies during COVID-19. Our data strongly indicated that curative intent was associated with a lower 30-day mortality than palliative intent, and COVID-19 cases had the highest risk of mortality. Additionally, mortality appeared to be driven by male sex, BMI < 25, hormonal therapy, and number of cycles, while morbidity doubled with palliative treatments and reached 75% with COVID-19 cases. Morbidity was driven by age > 65 years, BMI < 25, chemotherapy, hormonal therapy, and immunotherapy. These data support the conclusion that curative and selected palliative anticancer treatments can be safely continued, thereby reducing the burden of accumulated delays in elective cancer surgeries. Avoiding delays in treatment could relieve pressure among oncologists and maintain good oncological outcomes among cancer patients.
Our data do not necessarily suggest that curative and palliative anticancer treatments can increase the COVID-19 infection risk, as only 3.6% (n = 89) out of 96.4% (n = 2370) of patients developed COVID-19 infection. This may provide confidence to oncologists to continue administering anticancer treatments during pandemics so long as appropriate protective measures are undertaken along with tele-oncology care. Our study highlights the importance of informed decision-making between oncologists and cancer patients on whether to withhold or continue anticancer treatments during pandemics. This study can contribute to existing literature by providing a benchmark that can be used as a reference for comparing the mortality and morbidity rates of curative and palliative anticancer treatments.
The 30-day mortality rate after anticancer treatment might be a useful clinical indicator for most anticancer treatment protocols. Stopping or delaying anticancer treatments during pandemics can lead to adverse oncological outcomes. Hence, understanding the outcomes of curative and palliative anticancer treatments as well as the outcomes for COVID-19 is urgently needed to help in clinical decision-making.