Staying Resilient: Understand The Risk of A Second Cancer

Contributed by: Dr See Hui Ti

While overcoming the disease once is challenging enough, the prospect of a new diagnosis can be daunting. Here is why it happens and how you can best prepare and protect yourself.

FOR CANCER SURVIVORS, THE JOURNEY TO RECOVERY EXTENDS BEYOND THE INITIAL TREATMENT. Integral to this path is follow-up care, which manages side effects from treatments, assesses one’s overall well-being, and ensures there are no signs of the disease returning. If all is well, the doctor will then discharge the patient from their care.

However, the joy of overcoming cancer can sometimes be marred by the looming worry of its return or the diagnosis of a second cancer.

Dr See Hui Ti, Senior Consultant, Medical Oncology, Parkway Cancer Centre, explains the difference between the two: “Cancer recurrence means that the first cancer has come back. On the other hand, a second cancer refers to a completely new cancer diagnosis, often affecting a different organ.”

Dr See, who specialises in breast and gynaecological cancers, acknowledges that the very thought of a second cancer diagnosis can be distressing, bringing back memories of the initial battle for both survivors and their loved ones.

However, she offers a silver lining: “The odds of getting a second cancer are actually quite low. Statistically speaking, a patient with breast cancer has half the chance of later developing colorectal cancer than someone who has never had cancer. The risk of developing cancer as a result of the treatment for your initial cancer is also low, ranging from two to 10 per cent.”

That said, awareness and understanding of the potential for second cancers can enable survivors to approach the future with knowledge and empowerment.


Low risk does not mean zero risk. The causes for a second cancer can be as varied as the first.

Lifestyle: Contributors such as smoking, being overweight or obese, and excessive alcohol consumption can heighten cancer risk — whether you have had it before or not. Genetics and family history play a part too.

Timing: If your first cancer diagnosis was during childhood, there is a marginally increased risk of developing a second one, possibly due to treatment effects or genetic predispositions.

Treatment: Studies show that treatment methods, such as radiation therapy and chemotherapy used to treat earlier cancers, may slightly raise the risk of a second cancer. Radiation therapy, for instance, could elevate the risk of leukaemia and solid tumours. These risks evolve over time. Leukaemia caused by exposure to radiation often develops within years of a patient’s treatment. Thereafter, the chance of developing a new cancer gradually declines. In contrast, solid tumours may take a decade or more to manifest after radiation exposure.

Other factors: The risk of solid tumours is also linked to the patient’s age at the time of receiving radiation therapy, the dosage used and the area treated. Some organs, such as the breast and thyroid, appear to have a higher risk for developing cancers after exposure to radiation.


While statistics on post-treatment risks may raise eyebrows, Dr See urges focusing on the bigger picture: “The immediate need to treat and potentially overcome the first cancer is paramount; its benefits far outweigh potential risks down the line,” she says.

Regular consultations with your doctor can provide peace of mind, as they can identify tell-tale signs of a second cancer. However, driven by anxiety about a possibility of a second cancer, some survivors might request tests for every conceivable cancer type. It is important to note that this is not recommended, as some invasive tests involving radiation can do more harm than good.

“Rather than requesting tests indiscriminately, it would be wiser to follow established guidelines for early cancer detection,” says Dr See. These guidelines specify screening frequencies and timelines for breast, cervical and colorectal cancer. “If necessary, we may refer to the Wilson criteria (see above), which provides a framework for determining when to test for a potential second cancer. If you are simply worried about another cancer diagnosis without any specific symptoms, I would advise refraining from excessive tests,” she adds.


While you cannot control genetics or past treatments, you can influence several factors to reduce future cancer risks. Just say no to:


Even e-cigarettes, which are prohibited in Singapore, are not a safe bet. They may lack some toxins found in traditional cigarettes, but they are not risk-free. E-cigarette aerosol contains various chemicals, some of which are carcinogens.

Excessive alcohol consumption

This is a well-established risk factor for various cancers, including breast, liver, mouth, throat, oesophageal and colorectal cancer. It damages cells and increases inflammation, both of which are pathways to cancer.

A poor diet

A diet low in fruits, vegetables and whole grains, and high in processed foods, red meats and sugary beverages, increases cancer risk. Such a diet may contribute to obesity and inflammation, both known risk factors.

A sedentary lifestyle

Low physical activity and prolonged periods of sitting or lying down are linked to higher cancer risk. They can lead to obesity and hormonal imbalances, raising the chances of cancer, particularly of the colon and breast.

The Wilson criteria for screening

  • The condition should be an important health problem.
  • The natural history of the condition should be understood.
  • There should be a recognisable latent or early symptomatic stage.
  • There should be a test that is easy to perform and interpret, acceptable, accurate, reliable, sensitive and specific.
  • There should be an accepted treatment recognised for the disease.
  • Treatment should be more effective if started early.
  • There should be a policy on who should be treated.
  • Diagnosis and treatment should be cost-effective.
  • Case-finding should be a continuous process.
POSTED IN Cancer Prevention, Life after Cancer
TAGS breast cancer, cancer diagnosis, cancer relapse, cancer screening, life after cancer