New Cancer Cases Rose from 3.37 Million to 5.15 Million in 15 Years: How Should We Look at Mutual-Aid Cost-Sharing?

The latest data from the National Cancer Center shows that new malignant tumor cases in China in 2024 were estimated at about 5.15 million. In 2011, when KangAi Commune was founded, the national estimate of new cancer cases was about 3.37 million.

Over the past dozen years or so, the total number of new cancer cases nationwide each year has grown by about 1.78 million. Seeing this figure, many members naturally connect it with the changes in mutual-aid cost-sharing in recent years: does more cancer mean contributions will keep rising?

The two are indeed related, but they cannot simply be equated.

First, an important piece of common sense: a rising total number of new cancer cases does not mean that each individual's probability of developing cancer has risen by the same margin.

Cancer is a disease closely tied to age. As the population ages, more and more people enter the age brackets where cancer is most common. Even if the risk of cancer at each age does not change noticeably, the total number of cases nationwide can still increase.

At the same time, diagnostic and screening capacity keeps improving, so some tumors that were once hard to find can now be detected earlier. Risk factors such as smoking, obesity, lack of exercise and dietary patterns are also changing, with some cancer types rising and others falling — China's cancer spectrum itself is constantly shifting.

So the move from 3.37 million to 5.15 million reflects the change in the cancer burden of society as a whole. Behind it lie population aging, but also changes in incidence risk, diagnostic capacity and the cancer spectrum. It cannot simply be read as "the average person's chance of getting cancer rose 50% in a dozen years."

This is also the first premise for understanding changes in KangAi Commune's cost-sharing.

The rising national cancer burden is the broad backdrop the Commune faces over the long term, but what determines cost-sharing more directly is the Commune's own membership structure.

The arithmetic of mutual aid is in fact simple: whatever mutual-aid contributions are payable under the community covenant in a given period is borne jointly by the members who meet the conditions for cost-sharing. So what really affects per-capita cost-sharing is the number of cases eligible for mutual aid, the mutual-aid amount per case, and the number and age structure of the members who share the costs.

KangAi Commune has been running for fifteen years, and the earliest members are now fifteen years older than when they joined; more and more of them are entering the age brackets where cancer and other major illnesses are most common. If too few younger members join in the meantime and the average age of the whole membership keeps rising, then even if the national cancer incidence rate were completely unchanged, mutual-aid applications inside the Commune could still increase.

There is another factor that is easily overlooked.

In the Commune's early years, a great many new members were still in the waiting period and did not yet have full eligibility for mutual aid, so the corresponding risk had not been fully released. As the years pass and more and more members come through the waiting period, the Commune gradually moves from a "young mutual-aid pool" toward a more mature pool that is closer to real long-term risk.

Conversely, if cost-sharing rises and more young, low-risk members choose to leave, while older members with stronger protection needs are more willing to stay, the membership structure may shift further. This is a risk that every long-term mutual-aid mechanism must guard against.

Therefore we cannot use one national cancer figure to explain simply why cost-sharing rose in a particular period.

Sometimes the national cancer trend changes little, yet cost-sharing inside the Commune may still rise because of its age structure, the number of members, or random fluctuation in cases. Conversely, even if society's cancer burden keeps growing, if the Commune can keep attracting new members of different ages and maintain a reasonable, stable age structure, the pressure on per-capita cost-sharing may be eased.

In the end, whether mutual aid can run over the long term does not hinge on there being more and more elderly people in society, but on whether the different age groups inside the Commune can remain relatively fair to one another, whether cross-subsidies become increasingly obvious, and whether such subsidies are acceptable to everyone.

This is also an issue we will need to watch particularly closely from now on.

Mutual aid has never been a product whose "price never changes"; it is a group of people jointly bearing risks that actually occur.

We will not promise members that cost-sharing will never rise, nor do we want to create anxiety with the idea that "major illness is on the rise." We would rather tell everyone the truth: the social burden of cancer and other major illnesses really is increasing, but the Commune's own age structure, the inflow and outflow of members, mutual-aid rules and risk control are equally — even more — direct in determining what each person ultimately bears.

So what the Commune really should do is not to find ways to prove that "every rise in cost-sharing is caused by external factors," but to do its own job well.

Keep promoting transparency of funds, public disclosure of cases, verification, and oversight through the Community Adjudication Panel and the members' own adjudication. Review every application strictly under the community covenant, guarding against fraudulent and ineligible claims. At the same time, pay more attention to the age structure of members and to long-term changes in risk, so that the rights and obligations of members of different age groups are as fair as possible.

Every contribution, after all, is the members' own money.

The meaning of mutual aid is that today everyone makes a small contribution that an individual can afford, to help one family bear a large risk it could not bear alone; and in the future, when that risk falls on oneself, this community will help in turn.

What we really need to defend is not a cost-sharing figure that never changes, but a set of mutual-aid rules that are fair, transparent and sustainable over the long term.

As long as that remains, mutual aid still has its value.