Lung Cancer in India – The
Past, Present and Future
S.K. Jindal,
MD (Medicine), FAMS,
FCCP, FNCCP
(Former Professor
& Head, Department of Pulmonary Medicine,
PGIMER, Chandigarh, India)
Medical Director
Jindal Clinics, SCO
21, Sector 20 D, Chandigarh, India 160020
Lung
cancer, which now in India
is recognized as a major type of common and fatal cancers, was described as
‘rare’ to “extremely infrequent” about half a century earlier. It was in 1962 when an ‘increasing trend in
incidence’ was noticed in a report of 1570 cases admitted between 1955-59 in
teaching hospitals of Delhi, Lucknow, Calcutta, Bombay and Madras. Sporadic reports on lung cancer thereafter
appeared from different centres from India.
The Past
The
diagnosis of lung cancer in the past was primarily based on clinical features
supplemented with a chest radiographic examination. Histological and/or cytological diagnosis was
rarely made and often considered unnecessary and/or undesirable. The approach to both the diagnosis and the
treatment was generally nihilistic and dismissive. Nothing more than palliative radiation
therapy was offered in most cases.
The
boundary between “the Past” and the “the Present” however is unclear and
arbitrary. There had been a continuous
growth in prevalence reports, recognition of risk factors and advances in
diagnostic and treatment modalities.
Some of the important observations which were made in the 1980s related
to the similarities between the contemporary epidemiology of lung cancer in India to that
in the Western countries about 40 years earlier. It was commoner in males, between 4th
to 6th decades of life, and with a strong smoking association.
The Present
The period
around a decade before and a decade after the end of the 20th
century has been significant in the overall attitude and approach to lung
cancer in India. The problem was recognized and reported from
several different parts of India. Most importantly, the role of tobacco smoking
in causing lung cancer was firmly established and reported. The higher odds ratios of lung cancer for
tobacco smoking were also reported for different forms of tobacco smoking
including the cigarettes and the bidis.
Passive smoking or environmental tobacco smoke exposure was also shown
to increase the risk for lung cancer in women and other nonsmoker individuals.
There has
been an enormous expansion and wider availability of different methods of
diagnosis. The imaging modalities
multiplied both in numbers and in the types of available procedures. High resolution digital radiography,
computerized tomography, spiral CT scanning and magnetic resonance imaging have
made it possible to diagnose the lesion more precisely. More PET scans for detection of metastases
are being installed in different regions of India. Image guided fine-needle aspiration cytology
helped in a more firm diagnosis of small sized and peripheral lung
lesions. Similarly, bronchoendoscopic
techniques for diagnosis included the introduction of trans-bronchial and
trans-tracheal fine needle aspiration cytology and biopsy.
The wider
application of percutaneous, bronchoendoscopic, thoracoscopic and
mediastinoscopic procedures have made almost all the areas of lung approachable
to obtain tissues for histo / cytological diagnosis. Therefore, a greater reliance is now placed
on the histologically confirmed diagnosis, than the diagnosis based on only the
physical and/or radiological findings.
Histological
diagnosis has assumed greater importance not only to confirm the disease but also
to administer a more definitive form of treatment with chemotherapy,
radiotherapy and possible surgery.
Attempts are now made to classify lung cancer into small cell (SCLC) or
non-small cell lung cancer (NSCLC) and to stage the disease.
Although surgical resection is still rare to uncommon, the
options for medical treatments have widely increased. Several newer chemotherapeutic agents and
regimens have been introduced. Toxic
effects with the newer agents are relatively much less. There has been a survival benefit with the
introduction of more standardized regimens and other supportive care. Some other treatment options have also become
available. Local brachytherapy,
endobronchial stents for bronchial airway obstruction, targeted therapies and
limited surgical approaches are also tried.
But one
must admit that the cost of chemotherapy has tremendously increased which is
not necessarily parallel to the increase in survival benefit. This is especially relevant in the Indian
context, since a relatively poorer family may frequently find the increase in
survival of the patient by a few weeks as futile after loosing the lifetime
resources on treatment. The concept of ‘best supportive care’ and of ‘end of
life care’ for terminal and incurable disease has found an echo in the
comprehensive management plans of lung cancer.
A greater stress on palliative treatment to provide symptomatic relief
from intractable pain, breathlessness, sleeplessness, restlessness, anxiety and
depression is considered more important than continuation of “curative” or
radical treatments for the ‘end of life care’.
The Future
Some of the
future developments are easier to visualize while others are difficult to
imagine. There is an obvious stress on
an early diagnosis. Screening of high
risk populations to detect early lesions have proved to be generally futile and
cost-prohibitive all over the world.
But the average period from presentation to diagnosis is likely to
significantly decrease with the wider and cheaper availability of radiological
and bronchoscopic procedures.
Endobronchial ultrasound guided fine needle aspiration is particularly
helpful in lymph node staging in lung cancer.
Research is actively ongoing in the field of identification and
assessment of specific biochemical, immunological or genetic tumour markers for
their diagnostic and prognostic importance.
Some of the important subjects of interest in this field of early
diagnosis include the use of DNA micro-arrays and proteomics, the detection of
molecular targets (VEGF, FGF, MMP etc.) and parameters concerning tumour cell
proliferation and apoptosis (EGFR, p53, K-ras, rb, bcl-2); and novel approaches
such as the identification of cancer associated serum markers in mouse
models.
From
management point of angle, there are several therapeutic potentials including
in India. Because of the improvements in curative
resectional and reconstructive surgery, it is likely to be widely employed in
management. Hopefully, a larger number
of thoracic surgeons and oncologists, will opt to manage lung cancer. The advances in chemotherapy with new
drugs/combinations, adjuvant CT and salvage CT will continue to occur. Tumour targeting with drugs will help more
specific therapy. Other novel therapies
which may find a place in the treatment include the novel pathwas for immune
regulation, nanotechnology and new targets e.g. angiogenesis (inhibition of
mediators – VEGF).
Finally,
the palliative treatment as well as the end of life care will continue to
occupy an important place in the comprehensive management. This subject requires an equal or even
greater attention of the oncologists, physicians, patients and their family
members, and other involved partners.
No comments:
Post a Comment