Nurse Zulfa Anas was diagnosed with a rare form of bone cancer in 2006 and had relapses in 2010 and 2012.

Her now 12-year-old son, Muhammad Firdaus, used to ask her, when she dropped him off at school, if she would be coming home later.

She says: " There were a couple of times when I couldn't be home because I had caught an infection and had to be hospitalised. He thought I got sick because he wasn't there to stop it."

Firdaus became less fearful of letting her out of his sight after she told him what bone cancer was and reassured him he did not cause it.

Ms Zulfa, 46, who is wearing a morphine patch and has not been declared cancer-free by doctors, also started talking about death with Firdaus and his brother Amin, nine, after a close friend died of cervical cancer last year.

She says: "My friend had kept her condition from her two teenage sons till the very last stage of the illness, when she was already semi- conscious. At the wake, I could see how angry her sons were at being kept from the truth.

"They told me they had not said what they wanted to say to her. They also felt guilty for not spending more time with her."

When one parent comes down with cancer, this information should be shared with the children as early as possible, says Mr Travis Loh, principal medical social worker and counsellor from the National Cancer Centre Singapore.

For younger children, parents can use simple words such as "mum is very sick" to help them understand the condition. Other information that can be shared include the part of body affected by the cancer, the treatment and the side effects, such as hair loss and vomiting.

When death looks inevitable, Mr Loh says parents can prepare their children that the ill parent may die, but with the reassurance that this is not likely to happen immediately. They can still spend quality time together and they have another healthy parent to take care of them.

Mr Loh says some parents withhold such information from their children, especially the younger ones, because they do not want them to worry.

He says: "Children can see and hear what is happening around them. If you don't clarify their doubts, they can jump to their own conclusions about what's happening, drawing from their own understanding and imagination."

Preschoolers and lower primary children tend to see things from a more personal and subjective viewpoint, he adds, and may believe their parents are sick because they have upset them. Others may think cancer is infectious.

Teenagers may have a better understanding of cancer, but may not be mentally and emotionally mature enough to handle their worries. Hence, it is important for parents to answer whatever questions their teens have, says Mr Loh.

Besides keeping the channels of communication open, it is also important to keep to the children's routines as much as possible to give them a sense of security.

"Keeping to the familiar daily routines will give children space and time to better adjust to changes in a secure environment," Mr Loh says.

Father-of-four Keith Leong, 52, was determined to create such an environment when his spouse, a housewife, died in March 2005, two years after she was diagnosed with stage four stomach cancer.

He took nine months of no-pay leave to spend time with his three daughters and a son aged between seven and 12, after which he requested a portfolio that did not require travelling.

Now a vice-president in ITmanaged services, he says: "I took over my wife's role and continued to take the kids to their extracurricular activities in school and to private enrichment classes such as ballet and piano. I tried to have dinner with them every day and continued our family outings on Saturdays to the beach and parks."

His eldest child, Esther, who was closest to his wife, was the most affected. He says: "She used to be very bubbly, but after my wife's death, she'd often keep to herself and stopped talking much." She could not focus on her studies and did not do well for her PSLE.

But Mr Leong said he never stopped trying to initiate conversations with her. He also made it a point to continue one-on-one time with her, taking her out for a movie, meal or "whatever she wanted to do".

Esther, now 22 and a kindergarten teacher, says a conversation with her father a few years after her mother's death made her decide to slowly open up. "My father told me, I was the eldest in the family and the only one he could share his problems with. He told me that he wanted to be close to me, but it's difficult if I won't open up to him about my feelings," she recalls.

Support from family and friends also helped Mr Leong and his children cope with their bereavement. His parents, who live with him, helped him watch the children when he was not around.

He and his children also continued to hang out with three other families from church. He says: "While the men sat around to provide a listening ear to me, their wives helped me watch my children. Such outings helped me cope with my grief and, at the same time, gave the kids a sense of normalcy."

Family and friends also rallied around six-year-old Rex and his mother, Ms Laura Richardson, 38, when she was diagnosed with stage three breast cancer in September last year. Even though she had a helper, Ms Richardson, a single parent, got her mother to come over from England so Rex could be with "family" while she was in and out of hospital for surgery and chemotherapy.

Her mother stayed for two months, after which her father came for one month. After he left, about 10 friends, both expatriates and Singaporeans whom she had met through her work, filled the gap. They started a WhatsApp group so they could coordinate play dates for Rex and they also took turns to accompany her to chemotherapy sessions.

Ms Richardson, director of sports development at the Equestrian Federation of Singapore, is now cancer-free and says: "I am not one to ask for help, so I am very lucky to have such friends."

With all the support, she says her son has coped pretty well so far.

For 12-year-old Abinandan Panikumanan, support from the community played a big part in helping him cope with the grief of losing his father, 42, to lymphoma cancer two years ago.

An only child, he was enrolled in a tuition programme under the Singapore Cancer Society. He also took part in a three-day camp organised by the society where he learnt to be resilient and made new friends.

Social worker Jeslyn Nah says he is coping better now. "He was more quiet in the past, but now, he's more cheerful and willing to open up to others."

Abinandan says: "Now, whenever I feel lonely or sad, I will talk to my mother or friends, or I will play Lego. Sometimes, when I feel angry about the cancer that took my father away, I will go and punch a pillow."

• How did you help your children cope when you had cancer? Write to stlife@sph.com.sg