Source: Flickr user Eric Norris

Cancer of any type is a terrifying disease to fight. There are simply so many unknowns associated with cancer, such as why it occurs in one person and not the next and what triggers its growth in the first place.

This isn't to say researchers haven't made significant advances in the past four decades with the mapping of cancer genomes that should lend new theories on the best way to tackle aggressive and metastatic cancers. However, some cancer diagnoses unfortunately have a grimmer outlook than others.

Pancreatic cancer and lung cancer, for example, have seen only a minimal uptick in five-year survival rates over the past 30-plus years, per the American Cancer Society. And, for all we know, this could be due to improved education about these cancer types rather than genuine improvements in pancreatic and lung cancer treatment medications.

Much is left to be done for colorectal cancer patients
Another cancer type that's witnessed just a modest uptick in long-term survival rates over a three decade time span is colorectal cancer. Data from ACS shows that the five-year survival rate for colorectal cancer has improved from 51% in the 1975-1977 period to 65% as of 2002-2009. Although it should be noted that while survival rates for localized or regional colorectal cancer are much higher, metastatic colorectal cancer's long-term survival is just 13%. 

Source: Exact Sciences

The point here is we have an urgent need for earlier colon cancer detection devices, and to some extent device developers have heeded this call. Diagnostic device developer Exact Sciences (NASDAQ:EXAS) had its revolutionary Cologuard system approved last year as a means to detect cancerous and precancerous polyp growth in a person's colon utilizing only their stool. The system analyzes the DNA shed from the wall of a patient's colon and looks for abnormalities that would be present if cancer or precancerous growth were present.

Still, much needs to be done for those patients who do wind up with advanced stages of the disease. But could the answer to prolonging patient survival be as simple as taking a supplement commonly found in your medicine cabinet? A recently released study might suggest just that.

Is this medicine cabinet supplement the key to increasing survival?
According to research submitted this week by the Dana-Farber Cancer Institute to the American Society of Clinical Oncology in advance of its 2015 meeting, patients with metastatic colorectal cancer that had high levels of vitamin D in their bloodstream lived, on average, 33% longer (32.6 months) than advanced colorectal patients with the lowest levels of vitamin D in their bloodstream. Additionally, higher vitamin D levels led to a longer period of progression-free survival of 12.2 months versus 10.1 months in the lowest vitamin D group.

Source: Flickr user Colin Dunn

Researchers for the 1,043-patient study measured blood levels of 25-hydroxyvitamin D, which is produced in the liver from vitamin D, and used this measure as their marker to divide patients into subgroups. As noted in the study, the average for the group with the highest concentration of vitamin D was 27.5 nanograms per milliliter. By comparison, the average ng/mL for the lowest group was just 8 ng/mL.

Said Kimmie Ng, one of the medical oncologists behind the study, "This is the largest study that has been undertaken of metastatic colorectal cancer patients and vitamin D. It's further supportive of the potential benefits of maintaining sufficient levels of vitamin D in improving patient survival times."

Of course, this study will require plenty of additional testing before vitamin D is going to be recommended as a treatment for colon or rectal cancer. For instance, high vitamin D levels can be reached by maintaining a healthy lifestyle involving plenty of outdoor activities and eating a proper diet rich in vitamin D. Researchers did control for factors such as diet and exercise levels and still found a strong correlation in favor of vitamin D increasing patient survival, though nothing can be said with any certainty as of yet.

A major advancement potentially on the forefront
In the meantime, colorectal cancer patients are left with a handful of promising experimental drug candidates from a new class of drugs known as cancer immunotherapies.

Cancer immunotherapies work by retraining the body's immune system to recognize cancer cells that would otherwise go undetected. This way the immune system can focus on killing cancer cells and slow or halt progression of the disease.

Source: Bristol-Myers Squibb

The most prominent of cancer immunotherapies are anti-PD-1 inhibitors such as Keytruda from Merck and Opdivo from Bristol-Myers Squibb. Both are currently approved as later-stage treatments for advanced melanoma but hold a world of promise for other solid tumor candidates, including lung and colon cancer. For example, in November, Bristol-Myers and Five Prime Therapeutics announced a collaboration that would combine Opdivo with Five Prime's experimental immunotherapy FPA008 in six separate phase 1 studies, including colorectal cancer. Preclinical data suggested that the combo could lead to heightened tumor response compared to just using one or the other as a treatment for these six solid tumor indications.

Ultimately, we need additional research on all fronts for colorectal cancer patients. But on the bright side we are seeing advancements, even if they're more of the baby-step variety when we'd prefer if it was the leaps and bounds type. I, for one, hope additional studies demonstrate that vitamin D does indeed boost colorectal cancer patients' survival as it's an easy and inexpensive supplement to come by. By that same token, I'm also looking for substantial advances in treating solid tumors via immunotherapies. It's an encouraging time, and I look forward to a day when researchers can proclaim that they've discovered a cure for this terrible disease.