Comparison to other studies
The treatment of TBSCC remains a multidisciplinary challenge. The
treatment of a clinical N0 neck has been fraught with controversies and
differing opinions, particularly on the benefits of a prophylactic neck
dissection, the extent of dissection and the role of postoperative
radiotherapy. Regional lymph node involvement has negative impact on
prognosis. Morris (17) reported a 5-year disease-specific survival (DSS)
of 18.8% and 80.8% in node-positive and node-negative patients while
Nakagawa (20) found a 5-year estimated survival rate of 70% in patients
with negative regional lymph node involvement, but a significant decline
in estimated survival to 19% in patients with positive lymph node
involvement. Masterson et al(4) reported a 5-year overall survival of
0% in his cohort of TBSCC with positive lymph node involvement. The
negative impact of nodal metastasis on survival supports the argument
that complete surgical clearance of the tumour both at primary site and
in the neck is required irrespective of the presence of nodal
involvement.
.
Historically, elective neck dissections have been advocated for cN0
necks in patients with head and neck SCC thought to have a 20% risk of
occult cervical metastases. This recommendation was based on
risk-benefit analyses performed in the 1970s by authors such as Ogura et
al.(21) and Lee et al.(22). It was commonly accepted then that radical
neck dissections were the main surgical approaches of choice for total
disease clearance, which in effect also carries a higher morbidity with
the associated removal of the accessory nerve, internal jugular vein
and/or the sternocleidomastoid muscle. It is understandable why a 20%
cut off was a reasonable historic choice to balance the pros and cons of
the surgery. Since then, the surgical procedures for cN0 have evolved
from radical neck dissections to functional, selective and highly
selective procedures with consequent reduction in morbidity. These more
selective approaches have been shown to adequately remove pathology
while minimising morbidity such as shoulder dysfunction and have become
the more mainstay form of prophylactic treatment of cervical disease.
With the change in surgical technique over the years, it seems
reasonable to re-evaluating the 20% cut off point and accept a lower
risk of metastases as an indication for a selective neck dissection to
achieve adequate disease removal and pathological neck staging.