HIPEC- Also known as IPHC/Chemo-bath/HIIC (Heated Intraoperative Intraperitoneal Chemotherapy)/Intra-abdominal hyperthermic chemoperfusion
Dr. Arun Goel says, HIPEC is a specialised multi-modal treatment given to selected patients who are diagnosed with tumours involving the peritoneum (a serous membrane covering the stomach and intestines), which is due to either a primary malignancy (cancers starting in the peritoneum) or a secondary malignancy (cancer spreading to peritoneum from digestive or gynaecological malignancy).
Malignancies which qualify for HIPEC treatment:
- Pseudomyxoma peritonei
- Mucinous adenocarcinoma of the appendix
- Peritoneal mesothelioma
- Colorectal cancer
- Desmoplastic small round cell tumour
- Ovarian cancer
- Other cancers of gastrointestinal origin
There are two major steps to HIPEC: (a) complete cytoreductive surgical procedure (b) administration of heated chemotherapy inside the peritoneal cavity
The surgeon starts with removing the tumour from the peritoneum, trying to remove all that is visible to the naked eye (cytoreductive procedure). For this purpose, various organs may be removed including the uterus, ovaries, gall bladder, spleen, parts of the intestine, omentum, etc. Removal of peritoneum involved by tumour is a critical part of the procedure.
After cytoreduction, catheters are placed in the cavity, connected to a perfusion system that heats the chemotherapy solution and pumps it into & from the body. This perfusion system is an apparatus that heats the drugs in a saline solution and circulates them through the body so that a stable temperature is maintained throughout the process. Inflow catheters are responsible for bringing the medicine inside the body & the outflow catheters send it back to the perfusion system. Along with the catheters, there is special probe placed to check that the drugs are at the desired temperature (41 C). Once these instruments are placed, the surgeons close the abdomen with staples or stitches & turn the machine on, which completes the cycle within 60-90 minutes.
After the chemo-bath is completed, doctors drain the medicated saline solution, followed by rinsing the cavity with a non-medicated saline solution. The tubes & probes are removed, completing the procedure. The entire process can take up to 8 – 18 hours, depending on the extent of the visible tumours and the degree of difficulty associated to its removal.
The most effective combination of drugs used is:
- Gemcitabine + Pemetrexed
- Cisplatin + Dimethyl sulfoxide
- Mitomycin c + Fluorouracil
Sometimes, while heated chemotherapy is being administered, IV chemotherapy is concurrently given to enhance the potential & efficacy of HIPEC. This is known as ‘HIPEC plus’
The recovery period of this procedure is long. The patient gets their nutrition via a feeding tube or IV (intravenous) for up to 2 weeks after surgery to give the digestive tract much needed rest. The hospital stay is normally 2-4 weeks long. Depending on cancer, there might be additional chemotherapy sessions scheduled later on.
The patient feels fatigued for several months and is advised to push for increased activity levels every day.
How does HIPEC work?
Once the surgeon removes the tumour, there are chances that there might be residual tumour too small for the naked eye to register or cancerous cells remaining. Heated chemotherapy helps destroy these cells and reduce the risk of cancer recurrence. Following reasons discuss why heated chemotherapy is effective:
- The hyperthermia initiates a selective killing effect in malignant cells. Cancer cells are destroyed at 41 C whereas normal cells get destroyed at 43 C
- There is an increase in the cytotoxic effect of chemotherapy agents. This means that the hyperthermia enhances the tissue penetration of the administered drug
- There is intensification of the regional dose due to the intracavitary delivery of cytotoxic drugs, thus increasing their efficacy
Advantages of HIPEC:
- It is a single, intraoperative treatment rather than a conventional, multiple-week-long treatment.
- As only cancer cells are destroyed at 41 C, the normal cells are unaffected which is not the case in traditional chemotherapy
- The heat allows chemotherapy to penetrate a few mm & kill cancer cells that cannot be seen
- HIPEC doses can be larger than IV chemotherapy doses because HIPEC-doses are not absorbed by the body in the same way, resulting in fewer side effects
- Prevents chemotherapy resistance
- Fistula (Skin & Intestines)
Since this is an extensive procedure that only trained specialists can perform, the criteria to qualify for treatment is exacting:
Age: Those patients with advanced age are not ideal for this line of treatment
General body condition: The patient must be healthy apart from cancer. Presence of heart disease, diabetes or any other chronic illness disqualifies the patient
Severity of the malignancy: If the malignancy has spread beyond the abdomen, this line of treatment is not recommended
For those patients who do qualify for HIPEC treatment, they must contact the best hospitals in India to find out more. Those patients who have undergone HIPEC therapy have the following survival rates:
- 1 year – 81 %
- 3 years – 60%
- 5 years – 47 %
If untreated, the patient may not survive more than a few months after diagnosis