Keeping you up to date on recent developments in oncology
OSU researchers weigh in on photon v. proton struggle for supremacy . . . Proton beam therapy has always had a good reputation for some things, but cost was not one of them, hence giving the edge to photons, the source for gamma-ray treatments for tumors. However, a recent announcement by researchers at Ohio State University (OSU; Columbus, Ohio) have handed the edge back to the tiny photon, at least where treatment of spinal cord gliomas are concerned. In a Dec. 22 statement at the OSU website, Buckeye researchers have evidence suggesting that “certain subsets of patients have better long-term survival“ with gamma radiation, a photon-based radiation, and that the evidence shows that photon-based treatments “may result in better survival than proton-beam therapy, even in patients with more favorable characteristics.“ Principal investigator Arnab Chakravarti, MD, who chairs the radiation oncology program and is co-director of the brain tumor program at the OSU Comprehensive Cancer Center – Arthur G. James Cancer Hospital (Columbus), said in the statement that the findings “need to be verified in a larger number of patients, but they suggest that individuals younger than age 54, those with ependymomas and those treated with photon-based therapy versus proton-beam treatment have better overall survival.“ He added, “perhaps most surprising is that the subset of spinal-cord tumor patients treated by protons appears to do worse, even though they have more favorable pre-treatment demographics.“ This observation, he noted, “certainly warrants validation in a larger subset of patients.“ The issue is an important one given that, according to the statement, gliomas represent most spinal cord tumors, and develop in about 17,000 Americans annually. The vast majority of them, or 13,000 are said to die from the tumors.
Gardasil approved for anal cancer . . . FDA has approved an expanded indication for Gardasil, manufactured by Merck (Whitehouse Station, New Jersey) to include the indication of anal cancer. The company announced the news on Dec. 22 that FDA had approved the vaccine, originally approved as a vaccine to prevent human papilloma virus (HPV) from triggering cervical cancer, but the added indication expands the number of patients who can hope to ward off a lethal cancer type. According to the Dec. 23 FDA statement, the vaccine is approved specifically for prevention of anal cancers and associated precancerous lesions categorized as types 6, 11, 16, and 18, in males and females between the ages of 9 and 26. FDA gave the vaccine the nod in 2008 for cancers of the cervix, vulva and vagina, but the new indication might not amount to much in terms of sales. According to the American Cancer Society, only slightly more than about 5,000 Americans are diagnosed annually with anal cancer, although HPV is said to play a role in about nine of every 10 diagnoses. FDA emphasized that Gardasil will not ward off an existing case. Merck built its case for approval around a randomized trial of men who had indicated they had experienced intercourse with other men, and the vaccine was 78% effective in preventing two variants of anal cancer. Because the same two types were prevalent in women as well, FDA found the evidence sufficient to grant the expanded indication.
Image-guided radiosurgery moves ahead . . . The advent of radiosurgery and radiotherapy was seen as a boon to patients, but keeping track of how closely the radiation is hitting the tumor quickly proved problematic. Industry has responded vigorously to this need, and in a Dec. 16 statement, Calypso Medical (Seattle) and Elekta (Stockholm) announced “a master development agreement to jointly develop products integrating the Calypso System with Elekta's radiotherapy treatment technologies.“ Edward Vertatschitsch, PhD, president/CEO of Calypso, said in the statement that integrating the Calypso image guidance system “into Elekta's world-class radiotherapy technologies may facilitate the development of innovative treatment modalities for treating prostate cancer along with more problematic radiation therapy targets, such as the pancreas and lung.“ He noted further that near-term development objectives “include creating connectivity between the linear accelerator and the Calypso System for patient positioning during radiation delivery, which automates the process of re-positioning the treatment couch when the tumor moves out of a prescribed motion threshold.“ The agreement, Vertatschitsch, said, “will also provide the framework for the potential development of real-time automated correction, a future capability with feasibility work already in progress at both companies, which enables motion management with the tumor target based on real-time tracking data provided by the Calypso System.“ The statement describes Calypso's offerings as complementary to Elekta's hardware for delivery of intensity-modulated radiotherapy, including Elekta's Synergy and Precise linear accelerators. Elekta said that it is “committed to providing clinicians with open-systems connectivity to integrate third-party technologies. Jill Stief, director of product management for Elekta's oncology systems said, “effectively accounting for tumor motion may lead to improved treatment outcomes and patient quality-of-life“ and “in addition to Elekta's existing initiatives for localization and motion management, this agreement will allow us to leverage synergies in our respective technologies.“ The statement makes note of a May 2010 study published in the journal Urology titled “Assessing the Impact of Margin Reduction,“ which is said to have demonstrated that patients whose radiation delivery was guided by the Calypso system experienced a significant decrease in side effects compared to patients whose radiation treatment did not include the Calypso guidance system.
Study suggests cancer risks associated with cellphones significant . . . The risk of cancer from living near electrical power lines came to be seen as the stuff of urban legend, a view that perhaps became popular with regard to the risk of contracting various kinds of brain cancer from extensive use of cellphones and other wireless technology. In a Dec. 20 statement at the website ElectromagneticHealth.org, however, the association takes square aim at the subject again, arguing that the risk of brain cancer from cellphone use is indeed significant. Citing the industry-funded Interphone study, a blog at the organization's website states that a Dec. 17 letter to the editors of the International Journal of Epidemiology from Lennart Hardell, MD, and his team at University Hospital (Örebro, Sweden) took aim at what the authors said were design flaws in the Interphone study. Noting that a study conducted by Hardell in 2006 showed an increased risk of about 180%, Hardell and his team argued that the Interphone results, which suggested a risk of about 118% over non-cellphone users, were flawed due to the omission of wireless land-line phones. The statement notes that the Hardell team “decided to reanalyze their own data on brain tumor risk using the more limited protocol used by the Interphone study,“ essentially trimming the data set to “subjects who were between 30-59 years instead of 20-80 years used by the Hardell team.“ Hardell and company then classified “any subject who used a cordless phone as 'unexposed', as the Interphone study had inexplicably done,“ and the tweaks to the Hardell data provided outcomes “that were statistically the same as the Interphone results,“ which the blog states “demonstrates [that] the lesser risk of brain cancers (gliomas) from cell phone use reported in the Interphone study was a result of the Interphone study's design flaws.“ The blog argues that the use of an age cohort from ages 20 to 80 and the addition of subjects using cordless phones would have rendered numbers from the Interphone study that would roughly equal the numbers found by Hardell, namely “a 180% increased risk of malignant brain cancers.“
– Compiled by Mark McCarty, MDD Washington Editor