LIFE09200604007 Tabish - Homi Bhabha National Institute

Review of Literature
The yet undeciphered extraordinary complexity of the disease cancer has
remained the “Achilles‟ heel” of scientific progress for many decades. This disease
with countable names, but uncountable causes, has been intensely studied with
inquisitive ideas using advanced technologies. Although these advances made in
prevention, diagnosis and treatment of the ailment have undoubtedly brought us a long
way in understanding cancer, but the outcomes have not enabled us to conquer the
disease yet, thereby leaving us still in the state of learning. The disease has even tighter
clasp on developing countries and India is no exception where one of the leading causes
of death is cancer. According to recent statistics the estimated number of cancer
incidences in India is approximately 9 lakh which claims over 6 lakh lives annually 1, 2 .
2.1 Upper aero-digestive tract cancer
Amongst all cancers, HNSCC including squamous cell carcinomas of UADT
are the most common cancers found in India with approximately 25% incidence rate 2 .
These cancers are also most prevalent amidst Indian men and are a significant problem
accounting approximately 40% of total male cancer burden (Fig. 1, Fig. 2) 2 . These
include cancer of the lip, tongue, major salivary glands, gums and adjacent oral cavity
tissues, floor of the mouth, tonsils, pharynx, larynx and other oral regions, nasal cavity,
trachea, bronchus and oesophagus (Fig. 3) 13, 14 . Mainly alcohol and tobacco habit,
alone or in combination, are associated with an increased risk of upper aero-digestive
tract cancers and their combined use has a multiplicative effect on risk 15, 16 .
Over the past decades a significant improvement has been observed in control
of UADT cancers owing to the introduction of improved diagnostic, surgical and
radiotherapy techniques and use of chemotherapy. However the achievement has not
been able to improve the overall survival owing to development of second/multiple
primary neoplasm(s) that occur more often in head and neck cancer patients than in
patients with cancers of other sites 5, 17 . There is around a 10-30% risk of development
of a second/ multiple primary neoplasm (s) or recurrence among the survivors of early
stage HNSCC during the first 5 years after initial diagnosis which poses an additional
threat in terms of morbidity and mortality 10, 18, 19 , with a relatively constant rate of
about 3-7% yearly 7, 8, 20 .
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