A recent analysis published by The New York Times is offering renewed hope to millions concerned about cancer, highlighting that up to 40% of cancer cases in adults can be traced back to lifestyle factors that are within our control to change (NYT, 2025). This finding underscores the significant opportunity everyone—regardless of family history—has to shape their own cancer risk through choices about smoking, diet, body weight, and exercise. For Thai readers navigating personal or familial cancer anxieties, these insights could not be more timely.
Cancer’s shadow looms large in Thailand, with over 190,000 new cases diagnosed annually and the disease ranking as a leading cause of death nationwide (WHO Cancer Country Profile, Thailand, 2020). Many Thais, like worried readers in the original New York Times article, see relatives struck by cancer and fear they are next. The latest research, however, affirms that while genetics play a role, most cancer cases—especially breast, colorectal, and lung cancers—are linked more to environmental or lifestyle choices than to hereditary gene mutations. Dr. Farhad Islami, senior scientific director at the American Cancer Society and lead author of the cited U.S. study, encourages patients: “That’s actually good news. You may be able to lower your risk by making better decisions for your health.”
For Thais with a family history of cancer, gathering a detailed family medical record is a crucial first step. Experts recommend closely tracking which relatives were diagnosed, at what ages (especially if under 50), and what types of cancer were most common. Dr. Amy Comander, medical director at the Mass General Cancer Center, explains that cancers emerging at younger ages or repeatedly affecting the same family lines (such as cancers of the breast, ovaries or colon) often hint at shared genetic mutations. “Look for patterns,” Dr. Comander advises. If several nonsmoking family members developed lung cancer young, for example, that suggests a genetic factor.
Genetic testing is becoming more accessible and could soon become routine for high-risk individuals in Thailand as well. Global and regional guidelines are evolving, and in some countries, insurance or public health services now cover costs for BRCA1 and BRCA2 gene testing (linked to breast and ovarian cancers), or for Lynch syndrome mutations (related to higher rates of colon cancer). Dr. Syed Ahmad, interim director of the University of Cincinnati Cancer Center, urges openness to genetic counseling: “A lot of times, patients are scared to go to a genetic counselor because of fear of the unknown. Having gene variants doesn’t necessarily guarantee you’ll develop a disease.” Thai readers should know this: if you test positive for a known cancer gene, you might undergo more frequent, earlier screenings instead of waiting until symptoms appear. Dr. Judy Garber from Dana-Farber Cancer Institute emphasizes, “You don’t want to miss that chance to find something early that could be curable.”
Still, Dr. Garber notes, genetics accounts for only about 10% of all cancer cases—a statistic confirmed by research in Asia and among Thai populations (PubMed: Cancer Epidemiology in Thailand). Many cases result from random DNA mutations or environmental exposures, so experts caution, “People should never blame themselves for getting cancer,” says Dr. Comander. Yet, several modifiable behaviors stand out for their impact on risk.
Smoking remains the leading preventable cause of cancer worldwide and in Thailand, where up to 40% of Thai men smoke, even as youth rates decline (Thailand National Statistical Office, 2021). The data are indisputable: quitting smoking, no matter your age, sharply lowers future risk. A 2021 review found ex-smokers quickly regain much of the cancer protection of lifelong nonsmokers (JAMA, 2021).
Maintaining a healthy body weight is equally crucial. Global consensus links obesity to at least 13 types of cancer, including the most common cancers in Thailand: liver, colorectal, and breast cancers (CDC: Cancer and Obesity). Thais’ changing diets—urbanization and the rise of processed foods—may be contributing to rising cancer rates, especially as traditional meals heavy in vegetables, herbs, and grains are replaced by high-fat and sugary Western fare. The latest advice: Favor fruits, vegetables, whole grains, and legumes over red and processed meats. Regular exercise matters too, says Dr. Alison Klein of Johns Hopkins School of Medicine: physical activity reduces cancer risk even if it doesn’t cause you to lose weight outright.
Thailand faces unique cancer risk patterns due to cultural factors. For example, bile duct cancer (cholangiocarcinoma) is unusually common in the northeast, traced to raw freshwater fish containing liver fluke parasites (Bangkok Post). The habit of chewing betel quid, still seen in some rural provinces, increases the risk of oral cancers (Cancer Research UK). Spiritually, some Thais believe “กรรม” (karma) or fate determines illness, which can discourage proactive health screening. Yet as Dr. Farhad Islami stresses, “Making better decisions can help—karma is not destiny when it comes to cancer risk.”
The future brings hope and responsibility. With genomic medicine becoming more affordable, more Thais could soon receive individualized risk profiles, integrating family history, genetics, and lifestyle. The government is investing over 150 million baht per year in nationwide screening and prevention campaigns as part of its Universal Health Coverage (UHC), aiming to further reduce cancer mortality (Thai Ministry of Public Health). At the same time, public health authorities warn of an impending obesity epidemic as processed foods become more widespread—a risk factor for both cancer and chronic diseases.
For practical action, Thai readers can: (1) Consult family elders to track a detailed cancer history; (2) Ask your doctor about whether genetic counseling might be appropriate for your family; (3) Quit smoking, or seek the many cessation programs now available at Thai hospitals and public health offices; (4) Favor a traditional Thai diet rich in vegetables, fresh herbs, and fish while avoiding processed meats and high-fat snacks; (5) Exercise regularly—even brisk walking in Lumpini Park or at the local ตลาด (market) counts; and (6) Don’t be afraid to schedule regular cancer screenings, especially if there is a family history or you are in a high-risk group.
As cancer cases in Thailand rise each year, the power of prevention is more vital than ever. Lifestyle is not everything, but as the science now shows, it is often more important than genes. Or, as a Thai saying puts it, “กันไว้ดีกว่าแก้”—prevention is better than cure.
Sources:
- How Can I Reduce My Risk of Cancer? - The New York Times (2025)
- Thailand Cancer Country Profile 2020 – WHO
- Cancer Epidemiology in Thailand – PubMed
- National Statistical Office of Thailand – Smoking
- JAMA – Smoking and Cancer Risk
- CDC – Obesity and Cancer
- Bangkok Post – Cholangiocarcinoma Campaign
- Thailand Ministry of Public Health
- Cancer Research UK – Betel Quid