The Elusive Search for a Cancer Cure: What's Taking So Long?
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The quest for a cancer cure often feels like a never-ending journey. Every few weeks, new headlines emerge touting breakthroughs in cancer treatments, yet the question remains: why haven't we found a definitive cure yet?
The transition from peer-reviewed research to sensational news coverage often leads to a distortion of facts. While the core information may stay intact, vital nuances can get overlooked, and the excitement surrounding new discoveries can escalate unnecessarily.
A pertinent example is the recent sensationalism surrounding the so-called "murder hornets" from Asia. As the sibling of a bee expert, I’ve encountered numerous misinterpretations and challenges stemming from media reports:
- These Asian Giant Hornets were not previously known as "murder hornets"; the term appears to be a recent media invention.
- The sightings of this species are limited to Washington state, not widespread across the country.
- While stings from these hornets can be lethal, they are not unique in this regard—30 to 40 wasp stings can also be fatal.
How did such relatively benign facts morph into a nationwide frenzy over "murder hornets"? And how does this relate to the search for a cancer cure?
The issue is that I frequently come across articles like these in my news feed:
- “Research Offers Hope for Cancer Breakthrough”
- “Scientists Make Progress in Liver Cancer Immunotherapy”
- “New Drug Reduces Tumors and Side Effects in Animal Studies”
- “Drug Found by Louisville Professor Could Treat Coronavirus” — even though it was initially promoted as a "cancer killer."
- “Researchers Unlock Key to Cancer's Emergency Brake”
All of these articles were released within the last month, each highlighting different drugs targeting various cancer types. (In order, these drugs involve micelles that correct cancer-controlling genes, immune system training against cancer, tumor growth inhibitors, synthetic DNA binding to cancer cells, and enzymes that slow tumor growth.)
It feels as though we are on the brink of conquering this disease, doesn't it? Surely, a solution must be just around the corner!
However, I have been seeing headlines like these for years, all proclaiming breakthroughs (breakthroughs! keys to cancer! miraculous new treatments! completely effective!). Yet, as far as I know, we still do not have a cure for cancer akin to treating an ear infection or an STD.
What is happening? Where is my elusive cancer cure?
Challenges in Translating Treatments Across Species
One of the significant hurdles in discovering an effective cancer cure is that not all scientists operate like the ones portrayed in movies.
In films, scientists often disregard ethical considerations and conduct experiments on humans without consent. While these scenarios typically involve extreme circumstances (like a zombie apocalypse or a mad scientist), the reality is that we cannot administer unproven, potentially dangerous treatments to people.
That's why researchers utilize cell lines and animal models. Cell lines consist of cultured cells in controlled environments, allowing for the testing of various cancer therapies. Additionally, scientists can induce various cancers in mice, providing a valuable avenue for evaluating potential treatments.
However, nearly two-thirds of "wonder drug" treatments that show promise in mice do not yield the same results in humans. The crux of the issue? Humans and mice are not the same—therapies that may be effective in one do not necessarily translate to the other.
Even in the most favorable outcomes observed in mice, treatments only successfully transfer to humans about 37% of the time. This means that nearly two-thirds of "wonder drugs" that cure mice do not have the same benefits in human patients.
So what do most of these promising articles discuss? Right—the results from animal or cell line studies. These often stem from academic labs that lack the funding for extensive clinical trials. The academic lab identifies potential drug candidates, demonstrates their efficacy in preliminary models, and then sells the findings to pharmaceutical companies capable of advancing these treatments to human trials.
These articles generate excitement about new therapies, but they often only celebrate the first step in a lengthy process—there are still numerous hurdles to overcome.
The Lengthy Journey of Drug Development
How long does it typically take to bring an anti-cancer drug to market?
- Six months to a year
- Two years to five years
- Five years to seven years
- Seven to fifteen years
If you guessed D, you are correct! The reality is discouraging, as it can take between seven to fifteen years.
Moreover, the cost associated with developing a single drug averages around $648 million. The likelihood of any one drug successfully reaching the market is less than 12%.
I wonder why journalists omit these statistics in their optimistic articles about new cancer treatments?
The slow and costly drug development process exists for a reason. It ensures that new medications are more effective than existing options and helps verify that they do not cause unreasonable side effects. These numerous stages of clinical trials are crucial.
Additionally, the FDA has special programs for orphan drugs—medications developed for rare diseases. Due to the limited patient population, pharmaceutical companies cannot afford full clinical trials, so the FDA allows for a faster, discounted process.
However, this typically does not apply to cancer drugs. Each of the exciting new therapies mentioned earlier must navigate the rigorous testing process, costing drug development companies as much as $2.7 billion before they can be prescribed to patients.
And this assumes they are even tested on the appropriate cancer type…
Cancer Diversity: A Complicated Battle
If given the choice, would you prefer lung cancer or breast cancer?
Some might assume it doesn't matter; after all, cancer is cancer. However, that assumption is incorrect. Treatment approaches and survival rates differ significantly among cancer types.
We are not combating one disease; we are facing thousands, each requiring tailored strategies.
For instance, lung cancer has a one-year survival rate of about 50%, while only around 16% of lung cancer patients survive five years. In contrast, breast cancer boasts a survival rate near 90%.
Even within a single type of cancer, there are various subtypes. Breast cancer tumor cells may be estrogen positive, estrogen negative, progesterone positive, progesterone negative, HER2 positive, or HER2 negative, or any combination thereof based on their molecular receptors.
This variability means that even if someone is diagnosed with "breast cancer," their prognosis can differ significantly. Localized, receptor-positive breast cancer has a five-year survival rate exceeding 99%, while regional, triple-negative breast cancer has a five-year survival rate of 65%.
Thus, each drug does not treat "cancer" in general. Each medication targets a specific cancer type. If your cancer has different characteristics, that treatment won't be effective.
We face not one disease but an array of thousands, each with unique attributes and requiring distinct approaches.
So, where is my promised cancer cure? Unfortunately, it:
- Has not yet demonstrated effectiveness in humans compared to animal or cell line models.
- Will require years to navigate the clinical trial process to confirm its safety and effectiveness without significant side effects.
- Likely targets only a few specific cancer types instead of addressing the myriad that exist.
Considering these factors, it is clear that we need to temper our enthusiasm for press releases that hype minor, incremental discoveries. Yes, some new drug discoveries could eventually become groundbreaking—perhaps five to ten years down the line after undergoing proper trials and testing.
We are making progress in treating cancer—across various types—but it is unlikely that we will find a "silver bullet," regardless of what a press release may suggest.