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Biotech / Medical : Biotech Valuation -- Ignore unavailable to you. Want to Upgrade?

To: Biomaven who wrote (9154)	9/17/2003 6:01:28 PM
From: Biomaven	Read Replies (6) \| Respond to of 52153

(A very OT post that I hope doesn't get totally out of hand...) Going very much out on a limb at this early stage, I predict that Wesley Clark will be the next Democratic nominee for President. If I'm correct, the ensuing election will be close and determined by events in Iraq between now and November 4th next year. Peter

To: Biomaven who wrote (9154)	9/17/2003 6:42:04 PM
From: Icebrg	Read Replies (3) \| Respond to of 52153

Travel distance survival bias. That is truly amazing. This is the abstract. A short audio and slide presentation of the results is available at ASCO's site. (Registration necessary) I still don't know if I am really believing they reached the correct conclusion. asco.org Is travel distance associated with survival on phase II clinical trials in oncology? Abstract No: 2098 Author(s): E. B. Lamont, D. Hayreh, K. E. Pickett, M. A. List, K. Stenson, D. Haraf, B. Brockstein, E. E. Vokes; The University of Chicago, Chicago, IL; The University of Illinois Chicago, Chicago, IL; Northwestern University, Evanston Northwestern Healthcare, Chicago, IL Abstract: Background: Survival estimates from small single institution phase II chemotherapy trials in oncology often exceed those that are subsequently observed in larger multi-institution phase III randomized trials of the same therapies. One possible explanation for this is greater referral bias (and associated patient-level differences) in phase II compared to phase III trials. Specific Aim: We sought to determine if a proxy for referral bias, the distance patients travel for treatment, was positively associated with survival using single institution results of phase II cancer trials. Methods: We studied results of 111 patients treated at a single institution on one of four sequential chemoradiotherapy protocols for locoregionally advanced squamous cell head and neck cancer conducted over seven years, evaluating for associations between all cause mortality and the distance between patient residence and the treating institution. Results: Using multivariable Cox regression that adjusted for standard patient-level disease and demographic factors and neighborhood-level economic factors, we found that the distance patients traveled from their residence to the treatment center was positively associated with their survival. Treating distance as a continuous variable, we found that with every ten miles that patients traveled for care, the hazard of death decreased by 5.6% (HR 0.94, 95%CI: 0.90 - 0.99). Evaluating the association nonparametrically, we found that those patients living greater than 15 miles from the treating institution had only 17% the hazard of those living closer (HR 0.17, 95% CI: 0.05-0.59). Conclusion: We conclude that results of single-institution phase II clinical trials in oncology may be sensitive to referral bias. Because patient travel distance captures prognostic significance beyond disease stage, performance status, and comorbidity, it may confound the apparent relationship between a given therapy and survival on such non-randomized trials. More work is needed to determine what unmeasured factors travel distance is mediating

To: Biomaven who wrote (9154)	9/18/2003 12:33:28 AM
From: BulbaMan	Respond to of 52153

>>>...Randomized trials comparing a new regimen against a control or placebo offer the best protection against the risks of erroneous conclusions inherent in phase II trials...<<< Problem is that it's difficult to recruit patients for randomized clinical trials, especially those involving a placebo because patients fear they will receive the placebo not the new treatment being tested. Consequently, as pointed out in a two-part NY Times series in 1999 (May 16 & 17), doctors are frequently paid for recruiting patients, with especially ambitious doctors recruiting a disproportionate share of trial participants. Another 1999 NY Times piece (June 22) reported that a disproportionate number of patients recruited for clinical trials are uninsured and join the trial because they can't afford to pay for the standard treatment. Both of the above make it very likely that many clinical trials wind up testing a nonrandom sample of subjects, compromising the experimental data.