喉頭癌放射線治療後の再発に関する研究

抄録

The primary laryngeal cancers in 43 recurrent cases following treatment by irradiation were clinically classified and graded. Supraglottic cancer was found most frequently, in 22 (51%) of the cases, followed next in frequency by subglottic cancer. Graded as to severity, 33 cases (79%) belonged to T₃ or T₄, which indicates that the malignant growth was already fairly far advanced before radiotherapy. Macroscopic examination of the excised laryngeal specimens revealed infiltration of the recurrent cancer into the vestibule or the anterior commissure in 30 cases (70%).
The overall 5-year-survival rate was 37 per cent. The separate rates for T₂, T₃ and T₄ were 57 per cent, 39 per cent and 17 per cent respectively, showing poorer prognosis with advance in severity of the disease.
Histopathological examinations of sagittal sections of the right and left sides and through the mid-line of the excised laryngeal specimens revealed squamous cell carcinoma in each, mostly showing a high degree of differentiation with cornification in 33 cases (77%). Invasion of the malignant growth into the thyroid and cricoid cartilages was observed in 12 cases. Localization of the tumor to only one side was seen in only a small number (30%), most (70%) showing spread to the mid-line or to the opposite side.
Findings that appeared to indicate a very early stage of the recurrent cancer were found 1) around the abnormally developed area of cornification, 2) around necrotic areas, and 3) in contracted fibrous tissue. Post-irradiation changes such as ravaged blood vessels, swelling of the intima, disarrangement of elastic fibers of the tunica interna, atrophy of disappearance of glandular cells and degeneration of cartilage were observed.