25% of cancers diagnosed in Singapore are rare cancers – and young people are more likely to have them

A combination of both genetic and environmental factors could be behind why  cancers tend to inflict teens and young adults.
Business Insider

Birt-Hogg-Dubé, Von Hippel Lindau, sarcoma: you may not have heard of these uncommon foreign-sounding names, but they represent a change in life trajectory for a small number of Singaporeans who may have found themselves being associated with either one of them.

Everyone of these names are rare cancers diagnosed by the National Cancer Centre Singapore (NCCS).

It is estimated that rare cancers form up to 25 per cent of all cancers combined in Singapore, and are more common among teenagers and young adults. Over a five-year span, the overall survival rate from rare cancers is just 47 per cent, compared to 65 per cent for common cancers.

Dr Chan Yong Sheng Jason, consultant medical oncologist at NCCS, tells Business Insider in an email that some of the rare cancers he has seen here are: soft tissue and bone sarcomas, certain types of lymphoma (like Hodgkin lymphomas, T-cell lymphomas), as well as non-cutaneous melanomas (acral, mucosal, ocular).

According to SingHealth, sarcomas are rare but aggressive tumours that can affect a very wide variety of tissues and organs in the body, but generally arise from soft tissue or bony sites on the body. They comprise around 1 per cent of all malignancies, and only 60 cases were seen by the NCCS in 2013.

Lymphoma, is a type of cancer that develops in lymphocytes, which are a special type of white blood cell crucial to the body’s resistance to disease, SingHealth says.

An explanation on Penn Medicine’s website describes non-cutaneous melanomas as melanomas – a type of cancer that develops from pigment-containing melanocyte cells – found on parts of the body other than the skin, such as in the eye (ocular).

We asked Dr Chan some questions on the state of rare cancers diagnosed in Singapore, to understand the impact it has on people here.

Here are some of the insights he provided:


Scientifically, when is a cancer considered “rare” and when is it considered common?

Dr Chan: Rarity of a cancer is based on its incidence.

There is no uniform consensus – the Europeans adopt a cut-off of <6 per 100,000 per year, while the Americans adopt a cut-off of <15 per 100,000 per year.

Singapore has not adopted either standard definition, but it is noted that some other Asian countries like Japan have adopted the European definition.


Why are rare cancers more common among teens and young adults?

Dr Chan: We do not yet fully understand why these are cancers tend to inflict teens and young adults. It is likely a combination of both complex genetic and environmental factors.


Since these cancers are rare, is there a higher chance for them to be missed or misdiagnosed?

Dr Chan: In general when it comes to rare cancers, there may be limited information to guide clinical practice.

Delayed or incorrect diagnoses may sometimes occur, particularly if these cases were presented to healthcare providers who are not specialised in the area.

At a tertiary cancer institute, the diagnostic uncertainty is greatly reduced with specialist input from multiple disciplines with specific expertise and accumulated experience.

Nonethless, the diagnosis of rare cancers certainly remains a challenge and much more research is needed in this area.


What are some of the biggest issues patients diagnosed with rare cancers in Singapore face?

Dr Chan: These patients usually face a lack of information on the disease given its rarity.

There may or may not be standard approved treatments available, and recommended options may be based on small clinical trials or extrapolated evidence from other cancer types. In terms of clinical trials or research programs, these are comparatively fewer compared to common cancer types.

Given the above, patients with rare cancers often do worse in terms of survival compared to those diagnosed with common cancers.

The overall health burden is compounded by the fact that many of these patients with rare cancers are teens and young adults – the psychological uncertainties and physical burden of a cancer diagnosis on their personal life (school, work, family, etc) cannot be overstated.


How can Singapore improve the way these rare cancers are diagnosed and managed?

Dr Chan:  In Singapore, rare cancers are managed according to best available data and international guidelines.

The challenges that Singapore face in the management of rare cancers are not unique, and there is a global unmet need to improve on the care of patients with rare cancers.

Worldwide, there is an urgent need to tackle rare cancers by setting the priority for research efforts, developing new diagnostic tools, discovering new drugs, and increasing clinical trial activity.


Since rare cancers are difficult to study and treat, what are some options Singaporean patients have taken in tackling the disease?

Dr Chan:  I would encourage patients with rare cancers to tackle this problem by being proactive in understanding more about their particular disease through research participation.

At NCCS, there is ongoing research on the molecular and genetic understanding of rare cancers, as well as efforts to conduct clinical trials in this area.

I hope that Singaporean patients with rare cancers can form a close collaboration with the healthcare team to understand more about their disease.

The saying that “there is strength in numbers” – this cannot be more true when applied to rare cancers.


Where would you suggest someone should start, if they become diagnosed with a rare cancer, but is unable to find more information or help locally?

Dr Chan: I would suggest that someone diagnosed with a rare cancer seek help at a specialist tertiary care center with the appropriate facilities and expertise. We’re fortunate to have a strong healthcare system in Singapore with such facilities and expertise already available.

There is certainly much knowledge to gain from active participation in research studies as well as patient support groups.

In Singapore, there are also online resources available to provide relevant information.

Although information may be limited for certain rare cancers, don’t be afraid to share what you’re struggling with or ask for help from your medical team. No one should fight cancer alone!


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