Wednesday, 31 March 2010

Extraocular Retinoblastoma in India

Retinoblastoma is the most common cancer of the eye in children and accounts for 2.5 to 4% of all childhood cancers. When a child is diagnosed with retinoblastoma, the cancer may be limited to the eye globe (intraocular) or have spread beyond the eye globe (extraocular). The spread may be local (to the orbit and local lymph nodes) or more distant i.e metastatic. Delays in presentation in India lead to more than half of the children with retinoblastoma having the cancer spread outside the globe at diagnosis.

Sameer Bakhshi and his colleagues describe the treatment and outcome of 25 children with extraocular but non-metastatic retinoblastoma over a 5 year period (2003 to 2008) from one of the premier treatment centres in India. The overall survival figures are not given but at a median follow up of 28.5 months (nearly 2½ years) 13 of the 25 children had progressed/relapsed.

All those who progressed or relapsed, either refused or did not respond to second line treatment which implies that they would all ultimately die of the cancer. One also needs to consider that there were 51 children with extraocular non-metastatic retinoblastoma during this time period but only 25 opted for treatment. Many if not all of those who did not opt for treatment for various reasons are also likely to have succumbed to the cancer. These poor outcomes are all the more significant as majority of the children in India with retinoblastoma present late and the disease has spread locally or systemically. Hence, it is not surprising that the five year overall survival of children with retinoblastoma (all stages combined) is less than 50% while that in Europe and North America is 95% and above.

Tuesday, 30 March 2010

Childhood Cancer in India: An Introduction

Globally, it is estimated that 250,000 children under the age of 15 years develop cancer every year. Around 50,000 (20% or 1/5th) of these children are in India.
Both the above estimates are based on the incidence of childhood cancer being 125 to 150 per million per year.

We do not know, how many of these 50,000 children with cancer in India get diagnosed. Of those who are diagnosed, we do not know how many of them seek treatment. A significant proportion of those who do seek treatment, either refuse treatment when it is offered or abandon treatment within the first few weeks. Based on information derived from published studies and presentations at scientific meets we know that treatment refusal and abandonment rates vary from 17 to 62% depending on the type of cancer and treatment center.
Ref – Arora et al, Pediatric Blood Cancer, Dec 2007

Currently, nearly 8 out of 10 children with cancer get cured in resource-rich countries like those in North American and Europe. If we exclude those who refuse or abandon treatment, comparable outcomes for specific cancers are achieved in India in those treated at tertiary institutes like the Tata Memorial Hospital in Mumbai. However, at a population level, the five-year overall survival for all childhood cancers combined has been reported to be 37-40% from Bangalore and Chennai. This cancer registry data is a much more accurate representation of cancer outcomes across India although as it is from urban areas, it is also likely to be an over-estimate of the true survival.
Ref – Arora et al, Indian Journal of Cancer, Oct-Dec 2009