You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

Objectives: Corona virus-induced disease 19 (COVID-19) pandemic has globally affected the surgical treatment of cancer patients and has challenged the ethical principles of surgical oncologists around the world. Not only treatment but also diagnosis and follow-up have been disrupted. Methods: An online survey was sent through Twitter and by the surgical societies worldwide. The survey consisted of 29 closed-ended questions and was conducted over a period of 24 days beginning in March 26, 2020. Results: Overall, 394 surgical oncologists from 41 different countries answered the questionnaire. The predominant guiding principle was "saving lives" 240 (62%), and the different aspects of lock-down found hence large support (mean 7.1-9.3 out of 10). Shut-down of elective surgery and modification of cancer care found a mean support of 7.0 +/- 3.0 and 5.8 +/- 3.1, respectively. Modification of cancer care longer than two weeks was considered unacceptable to 114 (29%) responders. Hundred and fifty six (40%) and 138 (36%) expect "return to normal" beyond six months for surgical practice and cancer care, respectively. Conclusions: Surgical oncologists show strong and long-lasting support for lock-down measures aiming to save lives. The impact of the pandemic on surgical oncology is perceived controversially, but the majority was forced already now to accept what is inacceptable for many of their colleagues.
["Prevention"]