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Salivary bacteria linked to oral cancers
Newsdesk
Radiotherapy after mastectomy more common in men Sex is not a predictor of locoregional recurrence or survival in patients with breast cancer who have a mastectomy, but it does predict the probability of receiving radiotherapy, says research in Ann Oncol (published online June 22, 2005; DOI: 10.1093/annonc/ mdi274). Graham Macdonald, Aberdeen Royal Infirmary, UK, and colleagues showed that men with non-metastasised tumours are almost six times more likely to receive radiotherapy than are women. Other factors associated with use of radiotherapy after mastectomy were large tumour size, positive margin status, positive nodal status, and delivery of chemotherapy. Macdonald notes that many institutions offer adjuvant radiotherapy after mastectomy to all men with breast cancer because of a perception that they have a high tumour to breast size ratio, whereas adjuvant radiotherapy is offered to women in accordance
with known indications such as tumour size, margin status, and number of positive nodes. Marie Overgaard (Department of Oncology, Aarhus University Hospital, Denmark), agrees that much attention has been paid to locoregional control, and that practice might vary from country to country. Macdonald and colleagues identified all patients who underwent total mastectomy in British Columbia, Canada, between 1989 and 1998 and compared prospective data from 60 men and 4181 women. Patients were excluded if they had a T4 tumour (ie, clear requirement for radiotherapy) or if they were younger than 40 years. 10-year breast-cancer survival was the same for men and women (81% and 79%). Overall survival was 53% for men and 65% for women, but there was no difference when looking only at patients who received radiotherapy.
Median time from diagnosis to radiotherapy was longer for women than for men (118 vs 97 days), possibly because of more concern over locoregional recurrences in men, or because more women than men received chemotherapy, suggest the authors. In women, radiotherapy was generally withheld because they had good prognostic features, whereas in men, it was more likely to be because they had poor performance status. This might explain why overall survival was affected by radiotherapy: it was worse in men who did not receive radiotherapy than in women receiving no radiotherapy. Overgaard agrees with the authors‘ conclusion—that men should receive adjuvant therapy in accordance with similar guidelines as developed for women.
Claudio Csillag
Salivary bacteria linked to oral cancers
http://oncology.thelancet.com Vol 6 August 2005
state that alterations in tumour-cell receptors could change the adhesion of some species of bacteria. “Whether these bacteria are simply markers of OSCC or have some cocarcinogenic effect is as yet unclear. Our previous studies have indicated that presence of an OSCC lesion has a greater effect on salivary microbiota than either smoking or periodontal infections”, points out lead author Donna Mager (The Forsyth Institute, Boston, MA, USA). “At this time, we cannot rule out the possibility that these bacteria have a role in causation of oral cancer.” The findings have given rise to hopes of developing a non-invasive diagnostic test for oral cancer, which afflicts 400 000 people every year. Early detection can improve survival. However, further studies involving larger numbers of patients with OSCC as well as those with precancerous
conditions are needed to develop a diagnostic tool. The group plans to investigate how well saliva tests predict the progression of precancerous conditions toward oral cancer, besides exploring the relation between oral bacteria and various cancers.
Dinesh C Sharma
© Robert Harding Picture Library
The saliva of patients with oral cancers have raised concentrations of certain bacteria, and some of these bacteria can be used as diagnostic tools to predict oral cancer, according to research in J Transl Med (published online July 7, 2005; DOI: 10.1186/ 1479-5876-3-27). A comparative study of saliva from 45 patients with oral squamous-cell carcinoma (OSCC) and 229 healthy controls showed that levels of six common bacteria species—Prevotella melaninogenica, Leptotrichia buccalis, Capnocytophaga ochracea, Capnocytophaga gingivalis, Eubacterium saburreum, and Streptococcus mitis— were significantly higher in patients than in controls. When three of these species (C gingivalis, P melaninogenica, and S mitis) were used as diagnostic indicators, they correctly predicted 80% of individuals with oral cancer and 83% of controls. The authors
Capnocytophaga ochracea is one of six bacteria species seen in oral cancer
547
Radiotherapy after mastectomy more common in men Sex is not a predictor of locoregional recurrence or survival in patients with breast cancer who have a mastectomy, but it does predict the probability of receiving radiotherapy, says research in Ann Oncol (published online June 22, 2005; DOI: 10.1093/annonc/ mdi274). Graham Macdonald, Aberdeen Royal Infirmary, UK, and colleagues showed that men with non-metastasised tumours are almost six times more likely to receive radiotherapy than are women. Other factors associated with use of radiotherapy after mastectomy were large tumour size, positive margin status, positive nodal status, and delivery of chemotherapy. Macdonald notes that many institutions offer adjuvant radiotherapy after mastectomy to all men with breast cancer because of a perception that they have a high tumour to breast size ratio, whereas adjuvant radiotherapy is offered to women in accordance
with known indications such as tumour size, margin status, and number of positive nodes. Marie Overgaard (Department of Oncology, Aarhus University Hospital, Denmark), agrees that much attention has been paid to locoregional control, and that practice might vary from country to country. Macdonald and colleagues identified all patients who underwent total mastectomy in British Columbia, Canada, between 1989 and 1998 and compared prospective data from 60 men and 4181 women. Patients were excluded if they had a T4 tumour (ie, clear requirement for radiotherapy) or if they were younger than 40 years. 10-year breast-cancer survival was the same for men and women (81% and 79%). Overall survival was 53% for men and 65% for women, but there was no difference when looking only at patients who received radiotherapy.
Median time from diagnosis to radiotherapy was longer for women than for men (118 vs 97 days), possibly because of more concern over locoregional recurrences in men, or because more women than men received chemotherapy, suggest the authors. In women, radiotherapy was generally withheld because they had good prognostic features, whereas in men, it was more likely to be because they had poor performance status. This might explain why overall survival was affected by radiotherapy: it was worse in men who did not receive radiotherapy than in women receiving no radiotherapy. Overgaard agrees with the authors‘ conclusion—that men should receive adjuvant therapy in accordance with similar guidelines as developed for women.
Claudio Csillag
Salivary bacteria linked to oral cancers
http://oncology.thelancet.com Vol 6 August 2005
state that alterations in tumour-cell receptors could change the adhesion of some species of bacteria. “Whether these bacteria are simply markers of OSCC or have some cocarcinogenic effect is as yet unclear. Our previous studies have indicated that presence of an OSCC lesion has a greater effect on salivary microbiota than either smoking or periodontal infections”, points out lead author Donna Mager (The Forsyth Institute, Boston, MA, USA). “At this time, we cannot rule out the possibility that these bacteria have a role in causation of oral cancer.” The findings have given rise to hopes of developing a non-invasive diagnostic test for oral cancer, which afflicts 400 000 people every year. Early detection can improve survival. However, further studies involving larger numbers of patients with OSCC as well as those with precancerous
conditions are needed to develop a diagnostic tool. The group plans to investigate how well saliva tests predict the progression of precancerous conditions toward oral cancer, besides exploring the relation between oral bacteria and various cancers.
Dinesh C Sharma
© Robert Harding Picture Library
The saliva of patients with oral cancers have raised concentrations of certain bacteria, and some of these bacteria can be used as diagnostic tools to predict oral cancer, according to research in J Transl Med (published online July 7, 2005; DOI: 10.1186/ 1479-5876-3-27). A comparative study of saliva from 45 patients with oral squamous-cell carcinoma (OSCC) and 229 healthy controls showed that levels of six common bacteria species—Prevotella melaninogenica, Leptotrichia buccalis, Capnocytophaga ochracea, Capnocytophaga gingivalis, Eubacterium saburreum, and Streptococcus mitis— were significantly higher in patients than in controls. When three of these species (C gingivalis, P melaninogenica, and S mitis) were used as diagnostic indicators, they correctly predicted 80% of individuals with oral cancer and 83% of controls. The authors
Capnocytophaga ochracea is one of six bacteria species seen in oral cancer
547