Marylin Leitch thinks the surgeon as the primary warrior in the fight against cancer. It means that practicing and investigating surgeons study all aspects of cancer management including assessing risk, screening, diagnosis, performing primary treatment, assessing prognosis, directing patients to adjuvant therapies and pursuing long term follow up of the cancer patients.
More than ever surgeons can play an active role in clinical research. In fact they must be familiar with the genetic and molecular basis of cancer etiology, the methods of screening and detection, the latest surgical technologies, the prognostic features of tumors and staging features, the efficacy of adjuvant therapies, and the appropriate guidelines for followup.
The author cites the trials of the American College of Surgeons Oncology Group.
In the recent past, clinical trials group have focused on adjuvant therapy questions. Now a new group focuses on surgical questions: the technique of lymphatic mapping and sentinel node biopsy, the clinical significance of micrometastasis, the therapeutic value of radical lymphadenectomy and reducing the morbidity of cancer surgery
(Leitch).
Between the debated surgical techniques cytoreductive surgery is playing an important role as part of a multimodality treatment of patients with classically incurable disease.
In fact radio and chemotherapy may be potentially curative for microscopic tumors, but rarely cure the patients with gross tumors. In select patients the majority of tumor can exist in limited and surgically accessible body sites and safe debulking of gross disease by resection or ablation can be combined with chemotherapy or radiotherapy or both.
Cytoreduction diminishes the metabolic demands made on the host by tumor, increases the likelihood that repeated cycles of chemotherapy will reduce the number of viable tumor cells toward the desired endpoint of zero, and diminishes the chances of cancer cells developing drug resistance, that increases directly with the number of cancer cells and the time it takes to complete treatment.
Moreover cytoreduction interrupts the metastastic cascade.
There are a number of cytoreduction methods: surgical resection (for example for ovarian cancer and other gastrointestinal malignancies or hepatic tumors), cryoablation (for example for unresectable hepatic colorectal metastases or for prostate cancer), radiofrequency ablation (similar applications of cryoablation), ethanol injection (for example for hepatocellular carcinoma in cirrhotic patients), interruption of blood supply through embolization techniques (for example for metastatic neuroendocrine tumors, sarcomas, melanomas and hepatocellular carcinomas), laser ablation, photodynamic therapy (for example for carcinomatosis and sarcomatosis).
The patients who benefit most from cytoreduction are those with symptomatic tumors, slow growing tumors, and tumors responsive to other therapies, and those in whom the surgical procedure can be performed safely
(Mc Carter, Fong).
After decades that emphasized a more conservative tissue sparing, surgical approach to treating cancer successfully, there has recently been a reexploration of more radical approaches.
Cady want requestion these assumptions and again challenge the past beliefs to develop or riaffirm basic principles in surgical oncology.
With a different philosophy with respect to the previous authors Cady reaffirms that regional node metastases or nodal recurrence ( persistence disease) are indicators but not governor of survival. They express biologic features that relate to prognosis.
The capability of dissemination systematically resides predominantly with the original cancer and ceases with its complete resection. Local and regional nodal recurrence are not significant sources of renewed dissemination of malignant cells after the primary cancer removal.
Increasing the extent of operations or adjuvant regional radiotherapy to reduce the risk of local and nodal recurrence is not justified in terms of increasing survival except in advanced cancers with substantial recurrence rates (>20%).
According to Cady's opinion the prevention or destruction of distant vital organ metastases can increase cure after surgical resection. And this comes from earlier diagnosis through screening and adjuvant systemic therapy.
In the future it may come from high technology treatments discovered in the laboratory or developed in clinical settings, that cure only those patients who actually display a clinical cancer or a clinical metastases, sparing the great majority of patients the toxicity of non-specific therapy
(Cady).
References
A Marylin Leitch, MD, FACS. What's new in Surgical Oncology. Journal of the American College of Surgeon, vol. 192, n° 5, 624-639, May 2001.
Martin D Mc Carter, MD, and Yuman Fong, MD. Role of the cytoreduction in multimodality treatments for cancer. Annals of Surgical Oncology, 8 (1): 38-43, 2001.
Blake Cady, MD, FACS. Fundamentals of contemporary surgical oncology: biologic principles and the threshold concept govern treatment and outcomes. Journal of the American College of Surgeons, vol 192, n° 6, 777-792, June 2001.
