Monday, November 19, 2012

When A Prostate Cancer Patient's Luck Runs Out: A Miracle Drug?

Shown above: a micrograph of prostate cancer cells obtained via needle biopsy.

You've had your prostate cancer treatment and it's decimated your body - sent you into a microcosm of pain and humiliation, however it was done. For the least lucky survivors (often of radical prostactecomies - which one urologist has estimated sees 40,000 of every 50,000 surgeries as unnecessary) there can be hideous complications, such as vesiculorectal fistulas - which are abnormal channels formed after surgery between rectum and bladder. When these fistulas cannot be surgically repaired, a colostomy bag is often the result. In other cases, infections set in(perhaps from improper drainage of fluids)  which are treated with antibiotics which precipitate c.diff. (which my own wife nearly died from after taking a prescription of amoxicillin in December, 2006, for a sinus infection.)

But after going through all manner of turmoil, pain and recovery what if the cancer returns? What then? Worse, what if it's more aggressive than ever and breaks through the 'capsule' and invades bone and vital organs? Consider these appalling facts:

- In about a third of prostate cancer patients, the disease recurs, becomes resistant to treatment, and spreads to other parts of the body.

--The five-year survival rate for men with cancer that has not spread outside the prostate or has just spread to nearby areas is almost 100 percent. But in patients whose cancer has spread to distant nodes or organs, the rate drops to 29 percent.

In the first stat, researchers have learned a certain breed of prostate cancer exists in which the cancer cells actually adapt to the treatment. For example, in the case of hormone treatments (HT) whereby female hormones are administered to suppress testosterone production ( testosterone being the 'fuel' that energizes prostate cancer cells) the cancer cells then begin making their own testosterone.

Even men who undergo the treatment believed to be the "gold standard" - radical protatectomy- aren't out of the 'woods' by any means. This surgery, now done to the tune of nearly 50,000 times a year (with lots of moola lining the pockets of the urologists who perform it) depends on a firm skill set and let's face it, innate talent, as measured by something called the "positive surgical margin".  This is the frequency, usually given as a percentage, of leaving cancer cells behind over a number of 'n' surgeries performed.

In 2004, Dr. Peter Scardino of Sloan Kettering Memorial published a study documenting the differences in success of radical prostatectomies base on the positive surgical margins for 26 urologists who performed the surgeries at Sloan Kettering and Baylor. His finding? The best surgeon in the group left cancer behind in 10% of cases. The positive margin rates of the other 25 surgeons ranged from 11% to 48%.  Meanwhile the much extolled da Vinci robotic surgery isn't any better with similar statistics and incontinence and impotence rates that equal or exceed those for non-robotic procedures.

Now, if the remnant cancer cells are there, were aggressive, and can metastasize, then what? In Barbados, we say the patient is in duck's guts. Now, in most cases the  cell pathology would have disclosed that a cancer is "high risk" and requires supplemental treatment. In this case, HT is given supplementally to radiation or surgery.  Because the cancer is fueled by the hormone testosterone, HT assumes the guise of treating the cancer with testosterone-blocking hormone therapies. But even so, the cancer cells can develop the ability to make their own hormone and learn to survive, giving the disease the ability to progress.

If it progresses, especially rapidly, the patient's time and hope will have run out. (Partial apologies to a certain brother "pastor" who has declared this cancer is the means "god" chose to rid the world of the "spiritually cancerous"  - he needs to take a good long look in the mirror!) Until relatively recently there was no further hope.

Then, in June of 2012, a funny thing happened - actually a serious event as reported in the June 2 San Francisco Chronicle online. Researchers at the University of California- San Francisco discontinued a clinical study they were conducting with a drug to treat advanced prostate cancer. They discontinued the trial because they discovered the drug (called Zytiga) showed such remarkably successful results that the researchers believed all the participants needed to benefit. So both the "control patients" (on a placebo) and non-controls used it.  Zytiga uses a mechanism that allows the drug to get inside the cancer cell and block it from making its own testosterone.

This is HUGE! It means that a means has been found to diminish the cancer cells' fuel supply and hence slow growth. The advanced cancer patients by dint of this drug therapy managed to get 5-6 more years of life. The downside?  Zytiga - and a 'sister drug' Xtandi-  still aren't effective for all patients.  According to Dr. Eric Small, deputy director of UCSF's Helen Diller Family Comprehensive Cancer Center and principal investigator of the project

"We're already seeing resistance to these agents. The outcomes are fairly predictable and bad. Our patients die."

Even those who do well will eventually develop resistance because the cancer cells adapt and learn how to survive on even a tiny bit of residual testosterone, Small said. Some patients simply don't respond at all. Either way, there's no way for doctors to know how a patient will respond until the resistance occurs.

"We don't know who these patients are or why or how to treat them," Small said.

According to the SF Chronicle piece:

"Small is the leader of the "dream team," which beat out 13 other competitors for the $10 million award. The team, selected by the nonprofit American Association for Cancer Research, involves more than 30 investigators at six West Coast institutions: UCSF, UCLA, UC Davis, UC Santa Cruz, the Oregon Health & Sciences University and the University of British Columbia.

The team will focus on identifying the pathways the cancer cells use to work around the current therapies and figure out ways to inhibit them using a combination of treatments to reach those escape routes in multiple ways. "

Since then some positive fruit has been borne as workers in the U.S. and the United Kingdom announced in two studies that they had identified separate "signatures" for prostate cancer that could better determine the aggressiveness of the disease and could be used to predict survival. The studies were published in the journal the Lancet Oncology . According to UCSF's Small:

"These signatures tell you you have high-risk cancer, but they don't tell you why and they don't tell you what to do with it. What we're going after is fundamentally different: try to understand the pathways that are involved in developing resistance and using co-targeting agents to treat it."

Congrats to Eric Small and his team for providing advanced prostate cancer patients with even a small ray of hope with the new drugs. But let's hope much more rapid strides are made and soon. Prostate cancer has nada to with any "spiritual cancer"  but with an actual, real biological-chemical pathway peculiar to the cancer cells. These cells aren't controlled by "demons" nor are the men in whose bodies they grow- whether believer or unbeliever- in any way responsible for them, nor did "god" design those cancer cells as a means to get unbelievers into a fictitious "hell" faster. Only screwballs that merit being tethered to an ECT machine for life would believe so.

1 comment:

Elinor Phillips said...

the survival percentage for prostate cancer patient is low.And "When A Prostate Cancer Patient's Luck Runs Out" and there is a positive resistance to drugs? maybe its about time to try on alternative prostate cancer treatments.