More cancer patients die here than in US, South Korea, Japan: Paper

More than double the number of cancer patients in Singapore die of the disease compared with those in Australia and the United States. In Asia, Singapore also fares worse than South Korea and Japan in terms of cancer survival rate.

Doctors say factors such as age at diagnosis, screening take-up rates and access to care are among possible reasons for the lower survival rate here.

A paper published by the Asia-Pacific Medical Technology Association (ApacMed) in June showed that 51 out of 100 cancer patients in Singapore die, compared with 24 in Australia, 25 in the US, 38 in South Korea and 41 in Japan.

The paper suggests that countries with higher cancer mortality rates are the ones with lower use of next-generation sequencing (NGS), a test that identifies biomarkers in cancers that can be targeted with specific treatments, resulting in better outcomes.

ApacMed, which represents manufacturers and suppliers of medical equipment, devices and in-vitro diagnostics, clearly has an interest in pushing for NGS.

The paper admits that "there is an absence of current studies establishing a causal relation between mortality-to-incidence ratio and variations in NGS access".

However, it points out that there have been several studies showing better patient outcomes in countries where there is reimbursement for NGS, such as in South Korea for colorectal and non-small cell lung cancer.

Associate Professor Ravindran Kanesvaran, who chairs the division of medical oncology at the National Cancer Centre Singapore (NCCS), said: "While NGS has demonstrated potential as a tool that improves our understanding of a patient's tumour characteristics, it is inaccurate to say that its widespread implementation will have any impact on a nation's overall cancer mortality."

He added: "Many factors contribute to differing mortality rates across different countries, such as the overall age of the population at diagnosis; cancer screening take-up; genetic, environment and lifestyle factors; socio-economic status; access to care; the healthcare system and more."

He said more people in Australia screen for cancer than in Singapore. The screening rate does affect outcome, as cancer that is diagnosed early is usually more treatable.

The 74-page paper said there are no guidelines on the use of NGS in Singapore, that reimbursement is insufficient, and that there is low familiarity among surgeons and oncologists, with knowledge limited to centres of excellence such as the NCCS and the National University Cancer Institute, Singapore (NCIS).

It also said that in countries that do not have clinical guidelines on NGS use, there could be inconsistencies in clinical implementation of NGS testing in and across different types of cancers.

In reply to questions from The Straits Times, the Ministry of Health (MOH) said: "As part of the National Precision Medicine Strategy, the Ministry of Health is refining our overall approach to govern and facilitate the implementation of precision medicine on a sustainable basis."

An MOH spokesman said this includes working on the approach to govern the use of genetic and genomic test data. The ministry wants to ensure that new services and programmes that incorporate new technologies, such as NGS, are "evaluated for clinical and cost-effectiveness prior to mainstream adoption".

It is also investing in local capabilities and infrastructure to support the adoption of precision medicine technology.

MOH said that while precision medicine technologies allow for a wider range of genetic conditions to be detected, "more work is needed to establish the appropriate follow-up on the genetic results and guide appropriate, meaningful and practical clinical actions".

Prof Kanesvaran said that small-panel NGS is already routinely done for patients at the NCCS for specific tumours prior to targeted therapies being offered to them. "For example, in advanced lung cancer, over a third of patients who undergo NGS are recommended for targeted treatments based on the findings."

He added: "We also use NGS to identify patients suitable for clinical trials for novel therapies targeting specific biomarkers."

But he warned that NGS is not indicated for use in all types of cancer and must be used judiciously because of cost and the stringent data analysis required for it to be useful.

But his peers at the NCIS are more gung-ho about the use of NGS.

Associate Professor David Tan of NCIS' department of haematology-oncology said: "NGS has the potential to identify the Achilles heel in every tumour, which can, in turn, help to enhance the efficacy of cancer therapy by facilitating the better selection of patients for the most appropriate treatments."

Among several examples he gave was one for lung cancer. Prof Tan said being able to identify specific mutations can mean totally different treatments for patients.

One patient can simply be given tablets that can effectively shrink and control the disease for years, while another might require immunotherapy — or chemotherapy plus immunotherapy — to control the tumour.

He said the NCIS has been using NGS to help doctors identify potential clinical trial options for patients under its precision oncology programme since 2014.

Prof Tan was one of the authors of a paper published in the Frontiers In Oncology journal in May 2024, comparing the outcomes for breast cancer patients who had undergone NGS at NCIS.

Those who had targeted therapy experienced better progression-free and overall survival compared with patients who did not receive targeted therapy.

"Our ability to identify patients with rare or common mutations, who may benefit from novel targeted treatments that can be matched to their tumour mutation profiles, has enabled us to initiate trials of novel therapies in Singapore and has led to direct patient benefit," said Prof Tan.

He added: "NGS is increasingly relevant across a broad spectrum of cancers, but its value extends beyond late-stage cancers and can benefit patients with early-stage cancer as well."

Patients with early-stage endometrial cancers with a particular mutation would be offered additional chemotherapy, as this has been shown to reduce disease relapse and improve survival.

However, patients who have a different mutation which is associated with excellent outcomes would not need any additional chemotherapy or radiotherapy.

Knowing this would spare them the cost and toxicity of these treatments.

Said Prof Kanesvaran: "While NGS has demonstrated potential as a tool that improves our understanding of a patient's tumour characteristics, it is inaccurate to say that its widespread implementation will have any impact on a nation's overall cancer mortality."

Prof Tan agrees that there are other reasons for the relatively high deaths among cancer patients here, such as lower cancer screening rates leading to later diagnosis.

He added that there are also "lifestyle-related risk factors like obesity, smoking and excessive alcohol consumption, which can impact both the incidence of cancer and the patient's fitness to receive treatment, as well as individual socio-economic factors that may present barriers to accessing cancer care".

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