World Cancer Day, February 4th, 2025
By Dr. Caleb Harris M.Ch
Around this time last year, following the Meghalaya Cancer Conclave, there was a news report in the Shillong Times describing the event, wherein some cancer survivors had shared their experiences. One of them shared how she had to seek treatment outside the state as ‘Meghalaya did not even have a PET CT’. I was intrigued by the reason for making the long journey to a distant state, to a crowded hospital, stretching all resources-all for a test which is not even used for diagnosis, but for ‘staging’ the cancer.
The PET CT has caught the attention of the public, probably because of the deft marketing of this scan as the ‘one stop’ test for cancer, when in reality it is not. The Computer Aided Tomography(CAT) scan or CT scan has been used to study the internal organs of the body for long but the images are in varying shades of grey and need trained eyes to interpret them. The radiologist is a doctor who has acquired a postgraduate degree specialising in interpreting such images, but many doctors who deal with various diseases have a fair understanding of these scans. As a cancer surgeon, I read these images myself and discuss with our radiologist to understand certain nuances. However, the official report is prepared and signed by the radiologist, which is essential for medicolegal purposes.
While the CT scan helps us understand the ‘anatomy’(the structure of the human body) and the abnormalities, it has limitations in helping us understand the functional aspects. In order to improve the information obtained from CT scans, a (contrast) dye is injected through the veins while the CT images are acquired by the machine. This helps to delineate the organs better and can give insight into the functioning of certain organs. In the liver, the Contrast-enhanced CT scan can help us to diagnose certain conditions without even the need for a biopsy.
Cancerous cells of the body grow very fast and have more nutritional requirements than their normal counterparts. This is visualised by the Positron Emission Tomography(PET) scan, which shows these areas as possessing ‘hypermetabolic activity’. The PET scan is usually fused with a CT scan so that the best of both is made available. However, it is not only cancerous cells that show hypermetabolic activity. All infectious conditions, including tuberculosis, also show such activity, thereby confounding the results. In a country like India, with a high prevalence of tuberculosis, this leads to a lot of confusion. Hence PET CT is advised only for those cancers wherein research studies have shown proven benefit.
I remember treating a patient with early stage breast cancer who went to some other centre and got a PET CT done. This result showed that there was a small ‘lesion’(anomaly which needs to be characterised further) in the lungs. Being too small to be characterised further, she was operated upon and subsequently received chemotherapy too. She later came to us for follow up visits and would always be concerned over whether that lesion would be cancerous disease. Some other patients have had to undergo biopsy from lymph nodes near the heart as a PET CT showed some anomaly which was later found to be normal.
There are certain cancers, such as lung cancer, wherein if surgery is planned, it would be beneficial to undergo a PET CT. In such cases, we explain to the patients and advise them to travel to Guwahati to get this done, but this may not be absolutely essential in many cancers. However, it is common, especially in the metropolitan cities of India, to find patients walking into the consultation rooms of oncologists with PET CT reports. This has led to mushrooming of PET CT centres, the only positive being the competitive pricing, with the cost coming down to that of a CT scan.
So if not by a PET CT, how then is cancer diagnosed? The good old way, as I’ve known, is by clinical examination, wherein the patient shares his problems with the doctor, who, after further questioning, examines the relevant body parts and comes up with a ‘clinical diagnosis’. This is followed by a biopsy, which is a small tissue sample taken from the tumor, and sent for microscopic examination by a pathologist. While some cancers may need endoscopic examination for obtaining biopsy, others may need a CT scan or Ultrasonography to obtain tissue for biopsy. Once a diagnosis of cancer is made, the next step is to ‘stage’ it, to find the extent of spread(or lack of it). While traditionally the CT scan has been used, slowly the role of PET CT is being established in certain cancers.
The key is to understand that each and every cancer is different and may have to be treated accordingly, based on the findings of relevant research studies. This is the basis of ‘Evidence-based Medicine(EBM)’ which ought to be ideally followed in all centres.
World cancer day, observed on February 4th annually, is an initiative of the Union for International Cancer Control (UICC). The theme for this year is ‘United by Unique’, which places people at the centre of care and their stories at the heart of conversations. So it isn’t about treating a PET CT report but the person behind the disease who needs not just the treatment, but the care.
Research has shown that the best possible care that can be offered to cancer patients is Multidisciplinary Care, which means that specialists from various branches which deal with cancer get together to put in their efforts to obtain the best possible results. The core disciplines involved are Surgical, Radiation and Medical Oncology which are directly involved in the treatment of cancer. These are supported by the pathologists; the radiologists; the nuclear medicine physicians-who interpret the PET CT results; anaesthesiologists; critical care physicians; palliative care physicians; psychologists; medical social workers and many others. When these supporting physicians focus only on cancers, the outcomes improve. Thereby, we need onco-pathologists, onco-radiologists, onco-anaesthesiologists and so on.
Nuclear Medicine Physicians, apart from interpreting PET CT scans, can also provide treatment for certain cancers, especially thyroid cancers. This needs specialised equipment and personnel which are regulated by the government, in view of the potential radioactive hazards. Specially qualified technical staff are required, without whom the equipment will not be approved for use.
Sadly, we do not have any medical oncologists in Meghalaya. However, administration of chemotherapy is taken care of by Clinical Oncologists(a radiation oncologist who is trained in administering chemotherapy). While this may suffice for most cancers, treatment of blood cancers may need the expertise of medical oncologists. Apart from this, most of the other specialists are available at NEIGRIHMS. The post for Nuclear Medicine Physician has been advertised and a PET CT scan may be installed in due course, once we have the right manpower. However, considering the patient load, there is need for more specialists in all the disciplines.
While the government may procure equipment, manpower requirement is likely to be a stumbling block. The young doctors of the state should strive to equip themselves with the requisite degrees and come back to serve the state. The need for allied healthcare workers in related branches is also important and several youngsters can choose to join relevant courses.
So, does Meghalaya need the PET CT? Yes, but it is a test which is to be used for selected patients. Should patients seek treatment outside the state for lack of a PET CT? No. It is only a staging evaluation which may be necessary for certain cancers. Each and every patient is unique and may need to be treated in different ways, using Evidence-based Medicine.
Dr. Caleb Harris M.Ch.(Surgical Oncology) Additional Professor, Surgical Oncology, NEIGRIHMS (views expressed are personal)Email: [email protected]