論説 浸潤能評価に基づく舌癌の治療戦略

Invasion and metastasis are hallmarks of cancer and reflect the grade of malignancy. For oral tongue cancer, the depth of invasion has been incorporated in the T classification since the 8th edition of the UICC TNM classification. The invasive potential, namely, the pattern of invasion at the invasive front has been shown to be a prognostic factor in cases of tongue cancer. Several methods of evaluation of the tumor invasive potential, such as determination of the expression pattern of the laminin γ2 chain, assessment by the Yamamoto-Kohama classification, measurement of the tumor budding score, and determining the worst pattern of invasion, have been reported. High invasion potential as evaluated by these methods is recognized as a poor prognostic factor for late cervical metastasis of N0 tongue cancer, as well as for survival in patients with tongue cancer. After the initial surgery, evaluation of the tumor invasive potential at the invasive front of the primary tumor should be performed, in addition to measuring the depth of invasion and evaluating adverse features in the surgically resected specimens. Selection of the treatment strategy depending on the invasive potential might be useful to overcome the poor prognosis of highly invasive tongue cancers and establishment a better treatment policy, e.g., neck dissection, in cases of tongue cancer.

Invasion and metastasis are hallmarks of cancer and reflect the grade of malignancy. For oral tongue cancer, the depth of invasion has been incorporated in the T classification since the 8th edition of the UICC TNM classification. The invasive potential, namely, the pattern of invasion at the invasive front has been shown to be a prognostic factor in cases of tongue cancer. Several methods of evaluation of the tumor invasive potential, such as determination of the expression pattern of the laminin γ2 chain, assessment by the Yamamoto-Kohama classification, measurement of the tumor budding score, and determining the worst pattern of invasion, have been reported. High invasion potential as evaluated by these methods is recognized as a poor prognostic factor for late cervical metastasis of N0 tongue cancer, as well as for survival in patients with tongue cancer. After the initial surgery, evaluation of the tumor invasive potential at the invasive front of the primary tumor should be performed, in addition to measuring the depth of invasion and evaluating adverse features in the surgically resected specimens. Selection of the treatment strategy depending on the invasive potential might be useful to overcome the poor prognosis of highly invasive tongue cancers and establishment a better treatment policy, e.g., neck dissection, in cases of tongue cancer.