medwireNews: The presence of high levels of tumor-associated tissue eosinophilia (TATE) in early oral squamous cell carcinoma (OSCC) tissue can predict future occult lymph node metastasis, study results show.
Not only was a TATE intensity of 68-298 eosinophils/mm2 highly correlated with this type of metastasis, but also all of the regional recurrences observed in the study were in patients with intense TATE levels.
Around a third of clinically node-negative OSCC patients will reveal occult metastases during elective dissection surgery. Nevertheless, "a considerable number" of patients will remain node-negative, and could avoid the "undesirable cosmetic and functional effects of neck dissection," suggest Denise Oliveira (University of Sao Paulo, Brazil) and colleagues.
"Determining whether or not elective neck dissection will be beneficial to the patients with early oral and oropharyngeal squamous cell carcinoma remains an important clinical dilemma," they contend in Clinical Oral Investigations.
The team scanned 71 OSCC patients' tumor tissues for TATE, with 0-67 eosinophils/mm2 representing absent or mild levels, and 68-298 eosinophils/mm2 representing intense levels. The participants, aged a median of 59 years, all underwent elective neck dissection between 1977 and 2005 for primary OSCC located in the tongue or floor of the mouth.
A total of 36 patients' tissue samples contained mild eosinophilia, while 35 had intense TATE, and these latter tumors were significantly associated with current consumption of any alcohol, and/or a long history of alcohol consumption in addition to cigarette smoking.
During follow up, 12 patients experienced local recurrence, and six patients experienced regional recurrence. Notably, the latter patients were all in the intense TATE group.
Log-rank test results showed that TATE intensity was highly positively correlated with regional recurrence, remark Oliveira et al. Indeed, the 5-year regional disease-free survival rate was 100% for patients in the absent or mild TATE group compared with 82% in the intense TATE group.
Furthermore, the researchers found no significant differences between 5- and 10-year overall and disease-free survival rates in the absent or mild TATE group.
"Therefore, the intense TATE can be used as a predictive factor for occult lymph node metastasis and an adjunctive histopathological marker to reinforce the indication of elective neck dissection," concludes the team.
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