The GCO-002 CACOVID-19 Cohort: a French Nationwide Multicenter Study of COVID-19 Infected Cancer Patients

Since December 2019, China and then the rest of the world have been affected by the rapid development of a new coronavirus, SARS-CoV-2 (severe acute respiratory syndrome corona virus 2). The disease caused by this coronavirus (COVID-19), which is transmitted by air via droplets, is potentially responsible for a severe respiratory syndrome but also for a multivisceral deficiency that can lead to death.

In less than 3 months, the COVID-19 epidemic has already affected more than 440,000 persons and has been responsible for more than 20,000 deaths worldwide.

Cancer patients are generally more susceptible to infections than people without cancer due to immunosuppression caused by their tumor disease and/or conventional anti-cancer treatments used such as cytotoxic chemotherapy, several targeted therapies, radiotherapy or recent surgery. These patients may therefore be at particular risk for COVID-19.

This is suggested by the very first analysis on the subject, which reports data from the Chinese prospective database of 2007 patients with proven COVID-19 infection in 575 hospitals in 31 Chinese provinces. After exclusion of 417 cases without sufficient available clinical data, 1590 cases of patients infected with COVID-19 were analysed, of which 18 (1%) had a personal history of cancer. This prevalence was higher than that of COVID-19 in the general Chinese population since the beginning of the epidemic (0.29%). Lung cancer (n=5, 28%) and colorectal cancer (n=5, 28%) were the 2 most common cancers. Four (25%) of the 16 patients for whom treatment was known had received chemotherapy or had surgery in the month prior to COVID-19 infection, while the majority (n=12, 75%) were patients in remission or cured of their cancer after primary surgery. Compared to patients without cancer, patients with cancer were older (63 years vs. 48 years) and had a more frequent history of smoking (22% vs. 7%). Most importantly, patients with cancer had more severe forms of COVID-19 than patients without cancer (7/18 or 39% vs. 124/1572 or 8%, p=0.0003). Patients who had chemotherapy or surgery in the month preceding the diagnosis of COVID-19 had a significantly increased risk of the severe form (3/4 or 75% vs. 6/14 or 43%), which was confirmed in multivariate analysis after adjustment on other risk factors such as age, smoking and other comorbidities, with a relative risk of 5.34 (95% CI: 1.80-16.18;p=0.0026). Finally, patients with cancer deteriorated more rapidly than patients without cancer (13 days vs. 43 days, p<0.0001). The authors of this publication conclude with 3 measures to be proposed to patients undergoing cancer follow-up: 1/ consider postponing adjuvant chemotherapy or surgery in the case of localized and stable cancer, 2/ reinforce protective measures for these patients, and 3/ monitor very closely and treat these patients more intensively when they have a COVID-19.

However, the increased risk of SARS-CoV-2 infection and severe forms of COVID-19 in cancer patients suggested by this first study remains to be demonstrated given its limitations, already highlighted by other authors. Indeed, the number of patients is small and the population of cancer patients is very heterogeneous, with in particular 12 patients out of 16 who had recovered from initial cancer treatments (therefore without immunosuppression), half of whom had a disease course of more than 4 years.

Nevertheless, a second Chinese study has just recently been published, reporting COVID-19 data among 1524 cancer patients admitted between December 30, 2019 and February 17, 2020 in the Department of Radiotherapy and Medical Oncology of the University Hospital of Wuhan, the source city of the COVID-19 epidemic. Although the rate of CoV-2 SARS infection was lower than that reported in the first study, it was still 0.79% (n=12), which is much higher than the rate of COVID-19 diagnosed in Wuhan City during the same period (0.37%, 41 152/11 081 000). Again, lung cancer was the main tumor location observed in 7 patients (58%), of which 5 (42%) were undergoing chemotherapy +/- immunotherapy. Three deaths (25%) were reported. Patients over 60 years of age with lung cancer had a higher incidence of COVID-19 (4.3% vs. 1.8%). Thus, it appears that the risk of COVID-19 is actually increased in cancer patients, although again, less than half of the patients with lung cancer had a higher incidence of COVID-19.

Moreover, two more recent studies performed in patients treated in Hubei Province of China and in New-York city found that patients with cancer had significantly increased risk of death compared to non-cancer COVID-19 patients, especially patients with metastatic cancer and those who had recent surgery.

Therefore, many questions remain to date on the level of risk and the severity of COVID-19 in patients with active cancer, in particular those under anti-cancer treatment and in patients recently operated for localized cancer.