The study was not powered
to compare recurrence-free or overall survival between
the treatment groups. Such endpoints require a much larger
study because of the generally good prognosis of small
glottal carcinomas. Voice quality might change after the
first 2 years of follow-up, and a longer follow-up time may
be warranted. When the study began, the Voice Handicap
Index (VHI) had not yet been validated in the Finnish
language, and thus it could not serve as a subjective voice
evaluation instrument. Female patients were excluded
because of the infrequency of laryngeal cancer in women
and to achieve a more homogenous study population, and
therefore the results may not be applicable to female patients
with laryngeal cancer. Smoking habits may influence
the quality of voice, but these data were insufficient for
analysis.