The Wednesday prostate cancer news: January 14, 2009

Reports covered in today’s news commentary include:

  • Prostate cancer diagnosis in men of low socioeconiomic status
  • The commercial launch of a new gene expression test
  • Risks for secondary cancers following different types of radiation therapy
  • Adverse effects of brachytherapy with or without hormone ablation
  • Single-port, robot-assisted laparoscopic radical prostatectomy
  • ARQ 501, a preclinical agent for potential treatment of prostate cancer

Miller et al. have reported on the probable underscreening and underdiagnosis of prostate cancer among men of low socioeconomic status, and have evaluated trends in prostate cancer severity in an ethnically diverse cohort of low income, uninsured men served by a state-funded public health program in California. Using data collected between 2001 and 2006, the authors have shown that: PSA levels at diagnosis exceeded 10 ng/ml for 51 percent of enrollees; 50 percent had a Gleason score ≥ 7 or greater; 43 percent had a clinical stage of T2 or higher; 19 percent had metastatic cancer at diagnosis (and this proportion remained stable over time); of the men with non-metastatic cancers at diagnosis, 24 percent had tumors with low risk features (and the proportion of low risk cancers did not increase over time). A commentary on this study has also been published in the New York Times.

In a media release issued on Tuesday, Clarient, Inc., a company that provides specialized anatomic pathology and molecular testing services for pathologists, oncologists, and the pharmaceutical industry, today announced the commercial launch of a new gene expression test for prostate cancer. The test is based on a combination of four genes that the company says can identify the presence of prostate cancer cells of Gleason grade 3 or higher in prostate tissue. The association of these four genes with prostate cancer was orginally discovered by Health Discovery Corporation. The potential clinical utility and value of this test is still open to some question.

Takam et al. have published estimates of the risk of developing a second primary cancer (SPC) as a potential consequence of various radiation treatment techniques for prostate cancer. The average risk of developing an SPC was ≤ 0.6 percent for all treatment techniques but was lower with either low dose rate (LDR) or high dose rate (HDR) brachytherapy alone compared with any external beam radiation therapy (EBRT) technique. For LDR and HDR brachytherapy alone, the risk of an SPC for the rectum was 2.0 x 10-4 and 8.3 x 10-5 percent, respectively, compared with 0.2 percent for EBRT using five-field, three-dimensional, conformal radiation to a total dose of 74 Gy. Overall, the risk of developing an SPC for urethra following all radiation treatment techniques was very low compared with the rectum and bladder. Treatment plans which deliver equivalent doses of around 3-5 Gy to normal tissues were associated with higher risks of development of an SPC. The “New” Prostate Cancer InfoLink has noted the difference between these comparative risk data and the supposed absolute risk data published earlier this year and based on a retrospective analysis of SEER data.

Mols et al. have evaluated the impact of iodine-125-based brachytherapy alone as compared to iodine-125-based brachytherapy in combination with hormone therapy on patients’ health-related quality of life (HRQOL). The authors argue, based on their relatively short-term data in 312 patients, that “The differences in HRQOL between brachytherapy and brachytherapy with volume-reducing hormone therapy are small; they both decrease HRQOL and increase treatment-related problems.” For the patients who received hormonal therapy, treatment was initiated 3 months prior to brachytherapy and continued for a total of 9 months. The authors further note that a long-term, prospective study is needed to obtain a comprehensive appreciation of the impact of adding hormone therapy to brachytherapy over time.

Barret et al. have reported experience with single-port, robot-assisted laparoscopic prostatectomy in a cadaver and on at single patient at a highly experience laparoscopic surgery center in France. They report that this technique is “feasible.” The total operative time in the human patient was 150 minutes, with 500 ml of blood loss.

ARQ 501 (a formulation of β-lapachone with hydroxypropyl-β-cyclodextrin) is a novel anticancer agent with selectivity against prostate cancer cells overexpressing the NADPH:quinone oxidoreductase-1 enzyme. Because ARQ 501 lacks solubility, Dong et al. sought to develop an efficient delivery system for this drug by using β-lapachone-containing polymer implants (millirods) for direct implantation into prostate tumors. Their goal was to see whether the combination of a tumor-specific anticancer agent with site-specific release of the agent might lead to significant antitumor efficacy. The authors describe their initial results as “promising.”

4 Responses

  1. The conclusion of the Impact study: “Unlike the broader United States population the proportion of disadvantaged men with organ confined, low risk prostate cancer has not been increasing. Thus, while much attention focuses on potential overdiagnosis and overtreatment of men with screen detected prostate cancer, our findings suggest that for low income, uninsured men, underdetection and undertreatment remain significant concerns” says to me that the Manton Legislation that was submitted to the last Congress would have solved the problem. Unfortunately one of the big blocks for the legislation moving forward was the lack of approval for screening. What this does it appears is to set up a two-tiered medical care system in this country. Those who have money and insurance can be screened and treated for their potentially advanced prostate cancer but the same does not hold true for those who do not have adequate insurance or money. The IMPACT program is available for men in California but what about the men in the other 49 states?

  2. Kathy: Re the two-tiered American medical system. It doesn’t need to be set up. It’s been alive and well for 50+ years!

  3. Yes but there are programs for breast, cervical and colon cancer at CDC to screen and treat at least some of these people but because of the screening issues we can’t get anything pushed through for prostate cancer. The trickle through is that there are additional state funds for these cancers but men in Virginia who have prostate cancer can’t even get Medicaid funds. I don’t want those programs to stop but the attitude that you die with prostate cancer not from it and the lack of approval for prostate cancer screening gets in the way of getting much done unless it is done with private funds. I think it tends to distract from other activities that the prostate cancer community could do that are very important also. Because it has happened and is happening doesn’t make it right.

  4. No one is suggesting that any of this is “right” but you also can’t fight a successful war on five fronts at once, which is what the prostate cancer advocacy community has been trying to do for 10 years! We need to focus on one solid step at a time. If there are 10 steps that are equally important, then we just have to pick one, bring all our guns to bear on it. Achieve the objective and then move to the next step.

    We can’t keep hopping backwards and forwards between all 10 steps and hoping to climb the stairs! It’s poor strategy, and we keep repeating it.

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