Twelve years ago, Naomi Sakurai was diagnosed with breast cancer.

Then aged 37, she was a chief designer at an architectural firm in Tokyo. But her hard-won career trajectory was cut short by illness.

After eight months of temporary leave for surgery and chemotherapy, Sakurai returned to work. But being still in the early stage of recovery, she found herself fighting a new battle: It was difficult to carry heavy loads — and hard even to click a mouse after several hours of computer use. She sometimes had to miss important meetings when they coincided with her monthly hospital appointments.

Her employer was unsympathetic. Sakurai was the only cancer patient in the workplace and her boss questioned her ability to commit to the work. She resigned before the company could fire her.

"Later, I realized the significance of the thing I've lost. It was more painful to lose my job than to be diagnosed with cancer," Sakurai, 49, said.

"After quitting the job, I thought nobody would notice my absence even if I were to die, because I was no longer playing a role in society."

With advances in medicine, returning to work after treatment for cancer is now more possible — and more of an issue for the many people like Sakurai. In 2010, some 325,000 cancer patients were working, according to a government estimate.

Such people often face discrimination due to the stigma the illness carries. Many people still see it as a death sentence, when in reality, 60 percent of sufferers now have a five-year survival rate. And some observers say the government offers no support or protection for cancer patients in the workplace.

Because of this, a bipartisan group of Diet lawmakers drew up a bill to revise the Cancer Control Law to increase support for patients who want to balance medical treatment with their career.

The revised bill, which the group plans to submit to the Diet next week, stipulates for the first time the responsibility of employers to make an effort to continue employing cancer patients. It also stipulates that the government must promote general education about cancer.

The legislation also calls for creation of a society where cancer patients can maintain their dignity and social life. The bill is expected to clear the Diet by June 1, when the current session ends.

Sakurai, now heads Cansol, a job consulting firm for cancer patients. She welcomes the bill, saying it is significant that it stipulates creating a social environment that resolves many difficulties cancer survivors face in their daily lives.

"We, the cancer patients and our families, are part of society," she said.

The figures are stark. Half of people in Japan can be expected to contract cancer during their lifetime. In 2011, around 850,000 people were diagnosed with cancer, with about 30 percent of them of working age, according to the National Cancer Center's data.

A welfare ministry survey found about 34 percent of cancer patients quit their jobs or were dismissed in 2013. The percentage was unchanged from the previous survey, conducted in 2003.

"The big issue is that many people still regard cancer with a bias, thinking that once you are diagnosed it won't be cured and you can no longer return to society," said Miyako Takahashi, chief of the cancer survivor research division at the National Cancer Center. "Such labeling makes it difficult for employers to start thinking of ways for cancer patients to continue working in companies."

Akio Doteuchi, a senior researcher at NLI Research Institute, said creating a working environment for cancer patients is crucial for companies as well.

"Japan's working population will shrink. And it is becoming an increasingly big issue for companies to secure manpower," Doteuchi said. "When the time comes that more than 60 percent of cancer patients are given a life expectancy of at least five years, for companies to remain in business it'll be important to create a working environment for cancer patients to balance their treatment and job."

He said what needs to change is Japan's prevailing corporate culture, where regular workers are often expected to commit fully to the job and endure long hours.

"Many people have restrictions on working, such as illness, child-rearing, or nursing family members. It's important to create an society where everyone can continue to work while they have such restrictions," Doteuchi said.

Pundits say the important thing for cancer patients to remain in work is to give them more flexibility, such as shorter hours or allowing leave when treatment is required.

Also key to continuing working after cancer treatment is not to quit one's job, Takahashi of the National Cancer Center said, given that many cancer survivors face extreme hardship in finding work again. Even if they do not tell their potential employers about their past illness, they are questioned about unexplained gaps in their resumes.

Observers say a patient's typical response to cancer diagnosis is this: Many go blank for a few weeks. Then, some panic and quit their jobs, but they often regret the decision.

In a survey last year by Mitsubishi UFJ Research & Consulting Co., about 40 percent of former regular employees who quit their job after cancer diagnosis said they were hired as nonregular employees at new companies. But more than 90 percent of cancer patients who did not quit remained in regular employment.

"The goal is not for companies to provide cancer patients with special treatment," Takahashi said. "What is needed is justice, to treat them fairly. It is not fair to dismiss someone who has the will and ability to contribute to a company just because the worker has cancer."