Cancer Research Highlights
Cervical Cancer Screening Can Be Done Later and Less Often, According to ACOG
Women can be screened less frequently for cervical cancer with the Pap test (cervical cytology) than previously recommended, according to newly updated evidence-based guidelines issued November 20 by the American Congress of Obstetricians and Gynecologists (ACOG). Previously, adolescents were advised to begin screening within 3 years of becoming sexually active or at age 21 (whichever was younger) and to continue annually. Now, AGOG recommends that women wait until age 21 and then be screened every 2 years until age 30. Thereafter, following three consecutive negative tests, women should be screened once every 3 years. Women 30 and older can be screened with Pap tests and human papillomavirus (HPV) DNA tests every 3 years if their results are negative. The new recommendations appear in the December issue of Obstetrics & Gynecology.
These guidelines do not take into account whether a woman has been vaccinated against HPV, which is the cause of most cervical cancers. (Vaccinated women might be shown eventually to need even less frequent screening.) More frequent screening might be needed for women with certain risk factors, including those with weakened immune systems. Women who have had a total hysterectomy (and therefore have no cervix) and no history of high-grade cervical intraepithelial neoplasia should discontinue cervical cancer screening altogether.
This change to a more conservative approach is designed to “avoid unnecessary treatment of adolescents, which can have economic, emotional, and future childbearing implications,” the organization explained in a news release. “Although the rate of HPV infection is high among sexually active adolescents, invasive cancer is very rare in women under age 21.” And while HPV infections occur more often in younger women, their immune systems nearly always clear the infections and the associated cervical intraepithelial neoplasia within 1 to 2 years. If, however, these lesions are treated with surgery, adolescents who have most of their childbearing years ahead of them face an increased risk of premature births, as well as a greater need for caesarean sections.
Long-term Follow-up Provides New Insights on Adjuvant Therapy for Lung Cancer
Longer-term follow-up reports from two large, randomized clinical trials of chemotherapy delivered after surgery in patients with non-small cell lung cancer (NSCLC) have yielded disparate results. Published online in the Journal of Clinical Oncology, the findings come 2 years after clinical guidelines strongly recommended the use of post-surgical, or adjuvant, chemotherapy in certain patients with NSCLC.
The initial reports from both trials, based on 5 years of follow-up, found that adjuvant chemotherapy resulted in a statistically significant improvement in overall survival compared with observation following surgery. With longer-term follow-up (a median of 9.3 years), results from the smaller of the two trials, JBR.10, continue to show a benefit from adjuvant chemotherapy, with an absolute improvement in overall survival of 11 percent compared with observation. The survival improvement was strongest for patients with stage II NSCLC.
However, in the other trial, called IALT, after 7.5 years of follow-up, the initial survival improvement was not sustained, although there was a small but statistically nonsignificant improvement in overall survival. This was due in large part to an excess of deaths unrelated to cancer in the patients who received chemotherapy compared with those in the observation arm. In the JBR.10 trial, the authors noted, there was no difference between the groups in the rate of death from other causes or second cancers.
The results demonstrate that “longer follow-up is needed in the adjuvant setting…to assess cure,” wrote Dr. Jean-Yves Douillard of the Centre Rene Gauducheau in St. Herblain, France, in an accompanying editorial. Dr. Douillard explained that the JBR.10 trial only used the third-generation chemotherapy drug vinorelbine, along with cisplatin, whereas patients in the IALT trial received any of four chemotherapy agents along with cisplatin, including vinorelbine. In comparison with the other three agents (vindesine, vinblastine, and etoposide), he wrote, patients with lung cancer treated with vinorelbine have had a “consistent improvement in survival on a long-term basis.”
It is worrisome that the longer-term follow-up from the IALT trial did not show a sustained benefit, said Dr. Giuseppe Giaccone, head of the Medical Oncology Branch and Thoracic Oncology Section in NCI’s Center for Cancer Research. But some of the regimens used in the trial were “suboptimal,” he continued. Dr. Giaccone agreed with the recommendation on the adjuvant regimen of choice. “The largest experience is with cisplatin/vinorelbine,” he said, “and this is the regimen that should be used, unless there are contraindications.”
No Evidence that Hookah Smoking Is Less Harmful than Cigarette Smoking
Waterpipe smoking is a global phenomenon, especially among adolescents and young adults, driven in part by the belief that this method of tobacco smoking is associated with less exposure to toxic substances and fewer health risks than cigarette smoking. However, a recent study by Drs. Thomas Eissenberg of Virginia Commonwealth University in Richmond and Alan Shihadeh of the American University of Beirut, Lebanon, found that waterpipe tobacco smoking, commonly known as hookah smoking, is associated with greater exposure to carbon monoxide (CO), similar nicotine levels, and “dramatically more smoke exposure” than cigarette use.
The study, published in the December 1 American Journal of Preventive Medicine, involved 31 adults who were each tested after smoking one cigarette and after a 45-minute waterpipe smoking session. CO levels in the blood increased on average by 23.9 parts per million (ppm) after waterpipe smoking, versus 2.7 ppm after smoking a cigarette. The waterpipe smoking session generated more than 40 times the smoke volume compared with a cigarette. Peak nicotine concentrations were similar for cigarette and waterpipe use, but due to the longer duration of waterpipe sessions, “participants were exposed to 1.7 times the nicotine dose” relative to the dose from a cigarette, the researchers reported.
“These data provide no support for the notion that waterpipe tobacco smoke is less lethal than cigarette smoke,” Drs. Eissenberg and Shihadeh concluded. Instead their findings, along with other published studies, “suggest that waterpipe tobacco smoking is likely associated with many of the same tobacco-caused diseases as cigarette smoking, including cancer, cardiovascular and lung disease, and nicotine dependence,” the authors stressed. “Today’s challenge is to reduce current waterpipe tobacco smoking and prevent its further spread.” They expressed hope that their findings will be used by physicians and health authorities to counter public misperceptions about the relative harm of this type of tobacco use.
No Significant Change in Smoking Rate from 2007 to 2008
Although cigarette smoking in the United States declined by 3.5 percent from 1998 to 2008, the percentage of adults who smoke did not change significantly from 2007 (19.8 percent) to 2008 (20.6 percent), the CDC reported in its November 13 MMWR Weekly.
The CDC based its conclusion on results from the 2008 National Health Interview Survey (NHIS). Respondents were selected by random probability sampling, and the survey included questions on cigarette smoking and cessation attempts.
In 2008, an estimated 20.6 percent (46.0 million) of U.S. adults were current cigarette smokers. Of these, 79.8 percent (36.7 million) smoked every day, and 20.2 percent (9.3 million) smoked some days. In 2008, as in past years, smoking prevalence was higher among men (23.1 percent) than women (18.3 percent), and also varied by race/ethnicity, age, and poverty status. Pronounced differences were seen by level of educational attainment: 41.3 percent of individuals with a General Educational Development certificate (GED) and 27.5 percent of individuals with less than a high school diploma were current smokers, compared with 10.6 percent of individuals with an undergraduate degree and 5.7 percent of individuals with a graduate degree.
Between 1998 and 2008, the overall quit ratio (the ratio of former smokers to ever smokers) varied little and ranged from 48.7 percent to 51.1 percent. Here, too, differences were seen by level of educational attainment. “Persons with an undergraduate degree and persons with a graduate degree had quit ratios consistently higher than 60.0 percent,” the CDC stated. In contrast, “adults with education levels at or below the equivalent of a high school diploma, who comprise approximately half of current smokers, had the lowest quit ratios (39.9 percent to 48.8 percent).”
The CDC notes that effective population-based strategies for preventing tobacco use and encouraging cessation are outlined in the World Health Organization’s MPOWER package, and that “despite partial bans on some forms of advertisement, the tobacco industry continues to conduct targeted marketing towards socially disadvantaged subgroups and vulnerable populations, such as persons with low socioeconomic status and youth.”
Home Care Nursing Improves Cancer Symptom Management
Home care nursing (HCN) improves the management of symptoms in breast and colorectal cancer patients who take the oral chemotherapy drug capecitabine, according to a study published online November 16 in the Journal of Clinical Oncology. Researchers in the United Kingdom randomly assigned 164 patients with colorectal or breast cancer who were receiving capecitabine to either standard care or HCN and followed them for 4.5 months (6 chemotherapy cycles).
The study found that patients who received HCN experienced significant improvements in symptoms of oral mucositis, diarrhea, constipation, nausea, pain, fatigue, and insomnia compared with those in the standard care group. The benefits were most significant during the first two cycles of treatment. Individuals in the standard care group also had far greater unplanned use of health care resources, particularly days of inpatient hospital care (167 days versus 57 days for HCN patients).
An experienced nurse trained in home care and cancer care visited the patients assigned to HCN during their first week of chemotherapy. The nurse provided information about capecitabine and its side effects and answered questions during a 1 to 1.5 hour visit. Patients then received a weekly phone call from the nurse to assess side effects and discuss strategies for overcoming them. Patients who experienced multiple severe side effects (grade 3 or higher) or who otherwise had difficulty dealing with their chemotherapy received subsequent home care visits. Those assigned to standard care were provided with oral and written information about capecitabine by their physician and were prescribed medicines to deal with likely side effects. Patients who received standard care were assessed at baseline and then via a weekly telephone call from a research associate who did not provide medical advice.
Oral anticancer drugs are increasingly becoming part of the standard treatment regimens for many cancer types, so “it seems imperative to find ways to support patients at home,” the authors noted. A symptom-focused HCN program appears to be an effective way of providing that support, they concluded.