The Complexity of Cancer Classification

We often refer to “cancer” as a singular concept, yet we know that it encompasses a multitude of types, each with varying levels of severity. For example, the five-year survival rates differ dramatically among various cancers: individuals diagnosed with breast cancer have a 91% chance of surviving five years, whereas those with pancreatic cancer face only a 12% survival rate.

Moreover, different subtypes exist within these categories. For instance, breast cancer can manifest as ductal carcinomas, invasive carcinomas, inflammatory cancer, or triple-negative breast cancer, each requiring tailored treatment strategies.

Take triple-negative breast cancer as an example. This subtype lacks the three most common characteristics associated with breast cancer:

• Absence of estrogen receptors
• Absence of progesterone receptors
• Minimal production of HER2 protein, which is often targeted in breast cancer therapies

This absence of common markers limits treatment options. Other cancer types can often be managed by modifying hormone levels, but triple-negative tumors do not respond to such changes. Additionally, HER2 inhibitors are ineffective against these cells due to their low HER2 levels.

When we examine the broader spectrum of cancers—lung, brain, stomach, pancreatic, colon, bone, and skin cancers, to name a few—it becomes evident that “cancer” serves as an umbrella term for a diverse array of diseases. This complexity raises the question: how can we devise a universal treatment that addresses all these unique cases?

The Answer: Personalized Vaccines

In the clinical trial, each participant received a uniquely tailored vaccine. Researchers gathered samples of patients’ tumors through biopsies and identified the specific proteins with mutations on the cell surfaces. Consequently, a personalized vaccine was developed to target these unique mutated proteins.

For instance, if one individual had cancer cells with mutated proteins A, C, and D, while another had proteins C, F, and G, each would receive a custom vaccine designed to instruct their immune systems to attack the specific mutations in their tumors.

The breakthrough in this approach is the use of messenger RNA (mRNA).

Rather than providing the actual mutated proteins, we can simply supply the RNA blueprint for these proteins. The immune cells then produce and identify the proteins themselves, leading to their destruction. This method allows for faster production of tailored mRNA than traditional protein-based vaccines.

Limitations and Considerations

One might wonder: if we have a vaccine for cancer, does this mean a greater divide will emerge between the wealthy and the less fortunate? While the approach is promising, there are significant limitations to consider before jumping to conclusions about accessibility.

Firstly, to determine which proteins the vaccine should target, a tumor sample is necessary. This means that individuals must have already battled cancer and survived. Consequently, this vaccine won’t benefit young, healthy individuals who have yet to develop skin cancer, as we would lack insight into the specific genetic mutations that might occur.

Additionally, this approach is not infallible. The study was relatively small, and while the reduction in recurrence rates (22.4% with the new vaccine versus 40% with existing treatments) is notable, it doesn't guarantee immunity. Larger trials could reveal varying effectiveness or failure rates under different conditions.

Lastly, the cost of such personalized treatments remains uncertain. Given the need for specific tumor analysis and custom mRNA formulation, it's unlikely to be as affordable as mass-produced medications.