Young adults are more likely than either younger children or older adults to be diagnosed with certain cancers, such as Hodgkin and Non-Hodgkin lymphoma, melanoma, testicular cancer and sarcomas. However, the incidence of specific cancer types varies according to age. Leukemia, lymphoma, testicular cancer are the most common cancers among 15-24-year-olds. Among 25-39-year-olds, breast cancer, lymphoma and sarcoma are the most common.

Dr Eileen Poon Yi Ling, Consultant from the Division of Medical Oncology at National Cancer Centre Singapore, a member of the SingHealth group, answers questions about cancer in adolescents and young adults (AYA).


1. Question by c**********

My family has a history of cancer (both paternal grandparents passed away from cancer – stomach and lung respectively) and I am worried that my 9-year-old son may be at risk of either or just cancer in general. How can I be sure? Are there tests he can take that could possibly highlight a predisposition to it so that we can take preventive measures? Thanks a lot.

Answered by Dr Poon :

75%-85% of the cancers we see occur without a family history. They are what we call sporadic cancers. Lung cancer has a lower risk to be inherited.

Stomach cancer is known to be associated with some hereditary syndromes. However, these are usually associated with a strong family history of specific cancers (such as colon, breast, stomach cancers) and these usually present at a much younger age.

In addition, hereditary cancers usually have a pattern whereby almost every generation of the family is affected with a related cancer. In each affected generation, it is also not uncommon to find more than 1 person affected.

Hence, if its grandparents affected at an age of more than 70 years old, with no other family members affected, it is quite unlikely that the risk of inherited cancers in your family is higher than usual.

Lung Cancer

For lung cancer, if the risk factors or index of suspicion is high, a chest x-ray or a CT scan of the lungs can be done. Risk factors would include being a heavy smoker or exposed to a lot of second-hand smoke, certain types of air pollution and radiation.

Worrying symptoms would include:

  • Persistent hoarseness of voice
  • Persistent cough
  • Cough with blood being coughed out
  • Loss of appetite and loss of weight
  • Unexplained breathlessness

There are radiation risks to doing X-rays and CT scans, something I would be very concerned about especially in a 9 year old. I would not recommend this.

Stomach Cancer

For stomach cancer, risk factors would include:

- taking a lot of processed food - having history of stomach ulcer - history of gastritis with an infection of Helicobacter pylori

To investigate this, an OGD (Oesophagogastroduodenoscopy) would be needed. It is an invasive test where a scope is introduced into the mouth down the foodpipe into the stomach to check for abnormalities.

Worrying symptoms would include:

  • Feeling of fullness after eating very little
  • Vomiting blood
  • Passing stools that is hair-black in colour or blood
  • Repeated episodes of low red blood cells (with symptoms such as breathlessness, giddiness)
  • Loss of weight and loss of appetite

Without the above worrying symptoms, I would not advise for investigations to be done. Without the appropriate family history too, genetic testings would not be advised.

However, should there be above worrying symptoms or family history, I will suggest that you pay your GP a visit. He/she should be able to do the basic investigations and direct you to a specialist if necessary.

Take care!


2. Question by t****

My cousin, J, was about 10 months old when her mother (then aged 32) was diagnosed with cancer (lymphoma). Her mother was upset with what she thought was post-birth weight (she still looked pregnant!) that just wouldn’t budge despite going on various diets and exercise. Although J appears to be relatively healthy (she’s now 25 years old), she is worried that she might get a similar type of cancer when she enters her 30s. Is this type of cancer more common among young adults? And what can J do to lower or remove the risk of being diagnosed with this type of cancer? Thanks!   

Answered by Dr Poon :

Yes, Lymphomas belong to one of the cancers that are more common in those between 16-39 years old. There are some risk factors, but the cause of which is largely unknown. Most lymphomas are not hereditary, which means J should not have a higher risk of lymphoma because her mother had lymphoma. There is no specific way to lower/remove the risk of lymphoma completely. 

But what she can do is to lead a healthy lifestyle that includes:

  • No smoking
  • Alcohol in moderation
  • Exercise
  • Maintain a healthy body mass index
  • If a person has persistent gastritis, he/she may have Helicobacter pylori infection. This can predispose one to develop certain lymphomas
  • Avoid excessive/unnecessary radiation exposure
  • Safe sexual practices as HIV disease can predispose one to develop lymphoma
  • If there is a history of autoimmune disease in the family, it would be good to have this checked out as certain autoimmune diseases have a higher risk of lymphoma 


3. Question by h*********

My close friend has Acute lymphoblastic leukaemia (ALL) at 17 and is currently undergoing treatment. Would like to know if the cancer is curable and if not what is the survival rate in children with ALL? Thank you. 

Answered by Dr Poon :

Yes, acute lymphoblastic leukemia (ALL) is curable. However, this is also dependent on a few factors:

  • Age at diagnosis (older age tend to do not as well)
  • The white blood cell count at diagnosis
  • The DNA profile
  • Any other medical conditions
  • Ability to tolerate chemotherapy

Treatment is intensive, and usually proceeds on to allogenic transplantation or consolidation and maintenance with more chemotherapy. 

Your friend is lucky to have your support on this journey. 


4. Question by m*******

I heard that ovarian cancer does that only affect ppl in their 50s, it's becoming more common in teens and young women. What are some of the signs and symptoms that young adults should be looking out for then? Do HPV vaccines help prevent ovarian cancer? 

Answered by Dr Poon :

Dear M*******, Thank you for your question. HPV vaccines are targeted mainly at prevention for cervical cancers. They work because a good number of cervical cancers are caused by a Human Papillomavirus (HPV). Hence, the HPV vaccine works by preventing a person from becoming infected by HPV. By not becoming infected by HPV, the risk of cervical cancers can then be reduced. HPV is usually transmitted by sexual contact. 

In Ovarian cancers, the trigger and inciting factors are different from cervical cancers. About 15% of women with ovarian cancer can have HPV. However, the role of HPV causing ovarian cancer is uncertain, and this can happen because the patient has had exposure to HPV before. At this point, the guidelines for HPV vaccines are to prevent cervical cancer in a women who has not been exposed to HPV before. 

Many ovarian cancers are driven by the female hormones known as estrogens. For this reason, factors that increase the duration of estrogen exposure are associated. These include: 

  • High animal fat diet
  • No history of pregnancy or first pregnancy after 35 years old
  • Involuntary infertility
  • Late menopause or early age when menses started
  • A first-degree relative with ovarian cancer increases this risk by about 3 times
  • A genetic syndrome known as BRCA, which predisposes one to breast and ovarian cancers.
  • A genetic syndrome known as HNPCC (Hereditary Non-polyposis Colon Cancer). This syndrome predisposes one to ovarian and colon cancers 

The average age at diagnosis is about 60 years old, and this risk increases with age. Some of the common symptoms include: 

  • Persistent tummy bloating
  • Consumption of hormone tablets or certain oral contraceptives
  • Unexplained increase in girth size gradually, especially associated with swelling of the legs
  • A constant pressure in the lower back
  • Persistent changes in bowel movement
  • Urge to pass urine more frequently
  • Loss of appetite or feeling full easily
  • Nausea or vomiting
  • Changes in menses habits
  • Loss of appetite and loss of weight (or if weight gain is only around the tummy) 


5. Question by l******

My son had a sore throat and then “lost” his voice for a few days. Then when it came back, it sounded quite hoarse but there’s no pain. It has lasted more than 1 week now. We thought his voice was breaking (he’s 14 years old) or that the hot weather is making him “heaty”. I thought maybe he has mumps because his neck looked a bit swollen but he says there’s no pain. My friend says teenagers can get cancer too. Please advise. Thank you in advance. 

Answered by Dr Poon :

It is quite common for a bad bout of sore throat to last for a period of time. What your son had is probably “laryngitis” – inflammation/swelling of the larynx. This can result after a bad bout of runny nose/cough/flu. This is usually self-limiting and lasts less than 3 weeks. 

If his symptoms do not resolve within 3 weeks, I will suggest you bring your son to a doctor for further evaluation. 

There is a flu bug going around. Please take care! Do get flu vaccinations for yourself and family. But do take note that vaccinations can only be given when a person has recovered from his flu fully.  

6. Question by s****   

Are there support groups for teenagers with cancer? My friend’s daughter (she’s 19) has just been diagnosed with lymphoma and both are very upset. And now her daughter won’t talk to her and her behaviour has turned quite bad – she used to be a polite and outgoing child. We are very worried that she might have suicidal thoughts. Your advice please. 

Answered by Dr Poon :

We have actually just started a support group for adolescents and young adults with cancer. AYAs (Adolescents and Young Adults) usually fall between 16 to 39 years old, so your friend’s daughter definitely fits into this group. 

One thing is, lymphoma is generally a curable cancer. But it involves chemotherapy and potentially radiotherapy. Your friend’s daughter is also behaving in an expected manner. 

The diagnosis of cancer is devastating to anyone, much less to someone of this age group. Someone who is 19 is supposed to be in school or just starting out on their first job, making life plans. And this diagnosis essentially has thrown her a life’s curveball, with the future seeming uncertain and even bleak. Not to mention, all the scary investigations and information that is being thrown at your friend and her daughter, it can totally scare one off.

Some signs of active suicidal ideation would include: 

  • Making concrete plans to end their lives, such as driving to a spot on a certain day at a certain time to jump into the sea.
  • Start giving away his/her possessions and/or making a will 
  • Leaving goodbye letters behind

Even without active suicidal thoughts, she may also have depression as a result of such a devastating piece of news. She may benefit from talking to another young person with a history of cancer. 

Different people react to a piece of bad news differently, and not everyone will be open to the idea of a support group. 

In our support group, we aim to try and bring some sense of normalcy to their lives by organizing activities such as leather crafting and coffee appreciation. We also have a Whatsapp group chat that includes medical advisors and social workers as well. 

Should they have other questions, or would like to find out more first, you can contact my team and I at 


7. Question by m**********    

We have been trying to get pregnant for 3 years now and are not quite ready to seek medical assistance (e.g. IVF). I was wondering if maybe it’s my problem as I had cancer (ALL) when I was a child. I was treated with chemo for more than 3 years and I’ve been fine since then. Thank God! Could that cancer episode be a reason for infertility? Thank you. 

Answered by Dr Poon :

This is very relevant and you have brought up one very important issue in cancer survivorship in young adults – Sexuality and Fertility issues. 

ALL, or Acute Lymphoblastic Leukemia, is a blood cancer that requires intensive chemotherapy treatment. These chemotherapy agents oftentimes include anthracyclines (such as Doxorubicin, Daunorubicin) and alkylating agents (Cyclophosphamide, Ifosfamide). 

I am not certain if fertility preservation was available when you had your treatment. This should be offered routinely nowadays. Regardless, infertility is a common condition and is a condition that involves a couple and not just one person. This is also common in couples who have not had cancer. 

Infertility is usually defined as a couple being unable to conceive after 12 months of regular intercourse without use of contraception. Infertility is a major consequence of cancer and its treatment and is dependent on a few things: 

  • The type of cancer
  • The type of treatment
  • The duration of treatment
  • The intensity of treatment 

The more intensive the chemotherapy regimen, the higher the chance of infertility in future life. They can potentially affect the production of eggs and lead to premature ovarian failure in a female. 

So yes, it is possible that this may be related to previous treatment. However, there can be many other factors. I would strongly encourage you to visit a fertility specialist with your husband. Doing some basic investigations may help to determine if there is even an issue (or is stress a huge contributing factor), and what can be done if there is an issue. Sometimes, getting a checkup may help to allay fears and also help to make the process less frustrating. In addition, fertility treatments do not always equal IVF. Hence, it would be a good idea to find out more from your doctor. Good luck! :) 


8. Question by a*******
My children (8 and 11 years old) love swimming and I’d bring them down to the pool at least once a day. We use sunblock with very high SPF numbers and reapply when necessary. However, I’m still worried that too much sun exposure might perhaps cause skin cancer in the two kids, in their later years (teenager or a little older). Are oral sunblock pills recommended for children? Are there side effects? Assuming children can take the oral sunblock pills, will I still need to apply sunblock on my children? Thank you, doctor. 

Answered by Dr Poon :

Sunlight is essential for Vitamin D production and has many benefits. However, you are absolutely right and prudent in applying sunblock especially with global warming. 

Ultraviolet (UV) radiation has been shown to be associated with cancer, especially UV-B. UV-B represents only 5% of the UV radiation reaching earth’s surface. UV-A is more common, but its role in causing skin cancer is not as strong. 

You can also avoiding the sun during peak hours, wear sun-protective clothing for additional protection and using sunglasses and hats. 

To the best of my knowledge, oral sunscreens have not been fully approved nor endorsed. In such situations, this means that there is not enough evidence. Medical evidence comes from having large numbers (potentially in the range of tens to hundreds of thousands) of people having tried the particular medicine with its effects and results documented. This also means that the full range of potential side-effects may not be known. 

In such situations, I will especially not recommend that children consume them. They certainly cannot serve as replacements of physical sunscreens. 


9. Question by g******* 

Could my teenage daughter (now 13) get breast cancer? I have never heard of teenagers getting breast cancer but we have a history of breast cancer (2 aunts and a cousin) on my husband’s side of the family. How is it diagnosed and are there symptoms that we can lookout for? Can my daughter have a mammogram or is she too young? Thank you! 

Answered by Dr Poon :

You are absolutely right in that teenagers getting breast cancer is not common at all, especially at 13. However, never say never and it can still happen. 

Family history is important as breast cancer can run in the family. Hereditary (Inherited) breast cancer tends to occur young. 

Symptoms to look out for include feeling for a lump in the breast, especially if the lump is hard, has ill-defined edges, painful. The difficulty with this is that your teenager daughter is still developing, and as such the density of the breasts may be more difficult to feel. Not all painful lumps are cancerous, especially around menstrual periods. It may also be difficult for your daughter to feel as she may not know what to be feeling for. Other worrying signs would include: 

  • When the whole breast becomes red and swollen
  • When the nipple changes shape
  • Bleeding from the nipple
  • A lump in the armpit area that is hard and big 

I will suggest a few things: 

  1. Bring your daughter to a GP whom she is comfortable with, and get them to do a check for you. The GP should also explain the importance for your daughter to check herself regularly and teach her how to do it. 
  2. We have a genetics clinic at the National Cancer Centre Singapore who can go into greater details as to whether or not the history on your husband's side is worrying. If indeed it is, they will suggest some tests that your daughter can undergo, and whether it is acceptable to you and your family. I will suggest getting a referral letter from the polyclinic. 

A mammogram is really like an X-ray. So if there is indication to do so, it can be done. The main worry is with the radiation that becomes accumulated if we repeatedly undergo scans. Hence, I will suggest you get a mammogram only under the advice of a doctor. 

We usually use a triad of testing to diagnose breast cancer. 

  1. Clinical examination by a doctor
  2. Mammogram
  3. Biopsy if necessary 


10. Question by e*****   

We found out my teenager son has been chewing tobacco and smoking the water pipe. He has a sore inside his mouth where the cheek area is and it looks quite dark in colour. He won’t go to the doctor but we are still trying to make him. He says it’s tobacco stain. Do you think it’s mouth cancer? Are there other symptoms? My husband and I have no cancer history. Thanks! 

Answered by Dr Poon :

Yup, totally agree that it can be tobacco stain, especially after a prolonged period of chewing. Prolonged chewing may lead to a sore too. However, I also totally agree that you should get a doctor to check it out as cancers or pre-cancer growths can start with just a sore/ulcer. What the doctor will do, will be to feel for the area to make sure there is no lump. If there is, he/she would recommend for you to the appropriate doctor to get a biopsy. Symptoms that can suggest mouth cancer would include:

  • A persistent ulcer/sore that will not go away
  • Growth in the mouth that was previously not there
  • Persistent bleeding from the mouth
  • Developing of neck lumps that was previously not there
  • Painful swallowing of food and drinks 

Maybe you can strike up an agreement with your son. If after a week and the sore still persists, to then go to the doctor? Good luck! 


11. Question by a*******

Dear doctor My nephew (he’s 23) loves outdoor sports and I know he tries to do the right thing (apply and reapply sunblock and wears a cap etc…) when he spends a lot of time under the sun. I don’t know if they are tiny moles or freckles on his upper arms but they look like they have increased and changed in shape and size. I see him 1-2 times a week. I have suggested he wears those UV sleeves but he says they are too hot in our weather. Should I be worried? Thank you. 

Answered by Dr Poon :

Dear a*******, Thank you for your question! The sun can potentially result in increased freckles that can potentially darken with increased exposure. We tend to worry about melanoma when some of the signs below happen: 

  • When there is asymmetry of the lump/mole/freckle. This means that if you were to divide the lump equally into 2 halves, the 2 halves do not match up. 
  • The border of the lump/mole/freckle becomes irregular instead of a nicely rounded border 
  • If there is a previous mole, and the colour of this darkens 
  • The diameter of the lump/mole/freckle becomes gradually larger 
  • If a pre-existing mole starts to change in character, such as new bleeding, size, becomes bigger 

Other skin cancers that can be related to sun exposure include squamous cell carcinoma and basal cell carcinoma. Usually, it would be a lump that keeps getting bigger, with possible ulceration and bleeding. 

Applying sunblock is very important, and I'm glad your nephew does that. There are different types of sunblock with different SPF (sun protective factor). There are also sunblocks that can be water resistant. Maybe he can try those if he has not. 

UV sleeves add a physical barrier, and while that is good, it can be quite hot. I will suggest asking someone he is comfortable with to have a good check as a baseline whether there are moles/freckles anywhere, and in areas that he may not even realize. And perhaps, you can consider monitoring the moles/freckles? 

However, if indeed there is a definite change in size and shape, then please bring him to a doctor so that they can take a closer look and determine if a biopsy is needed. One other thing you can do is to consider making an appointment with the National Skin Centre, and they would be able to advise if these spots are worrying. 


12. Question by P**********

I am concerned that my maid (she is 38 years of age) has a 5.6 x 5.9 x 5.1cm circumscribed lesion of soft tissue seen in the right anterior mediastinum. What should I do next? We did not get any letter of referral from her G.P. What is the chances of her having lymphoma? She often loses her taste buds. She has mouth ulcers frequently. She often constipated. However she has good appetite and put on some weight after she joined me some two and a half years ago. 

Answered by Dr Poon :

Is this lump new or old, and is it increasing in size? And has your helper had any previous surgery done to that area? One possible cause could be non-cancerous, known as a lipoma, although I do agree that this is not a common place. However, if she has had surgery done to that area, it can also potentially be a keloid. If this lump is growing however, I will suggest her getting another opinion, and potentially even a biopsy as even benign lumps can turn cancerous, although that risk is low. 

Her age is an age where lymphoma can develop, although it tends to occur at an even younger age. At this age, breast cancer is more common; lymphomas tend to occur about 10% or less of the time. However, I agree with you that she needs to get this checked out as there can be other worrying growths such as: 

  • Thymoma
  • Thyroid cancer
  • Teratoma 
  • Germ cell tumor 

Common symptoms of lymphoma would include: 

  • Persistent unexplained fever 
  • Night drenching sweats 
  • Loss of appetite 
  • Loss of weight 
  • Lump that is growing in size 
  • Development of enlarged lymph nodes 

I will suggest you bring her to the polyclinic for another opinion.


About Dr Eileen Poon Yi Ling 

Dr Eileen Poon's passion is in Adolescent and Young Adult Oncology (AYAO), and she is working towards training specifically in this area. This is a field in its infancy, especially in Asia, combining both the science and art of Oncology and Medicine.

She recounts that, “Every single time I care for an AYAO patient, it never fails to humble and remind me why I am doing what I am doing. I hope to continue to learn, question and be an all-rounded oncologist, who is adept at treating patients with up-to-date science that is individualised to each patient.”

Ref: N18