Induction chemotherapy for advanced head and neck cancer

The role of chemotherapy for advanced oro and hypopharyngeal cancer

Although important progress continuous to be made in the treatment of oro and hypopharyngeal cancer, the 5-year survival rate for all this disease has remained at less than 30% for the past 30 years. In the early 1980s, chemotherapy was introduced with high expectation of reducing in the incidence of distant metastases and increasing the possibility of local control. This article explores the use of chemotherapy in the treatment of advanced pharyngeal cancer. Thus, the efficacy of chemotherapy are reviewed and treatment options for advanced pharyngeal cancer are made. When advanced carcinoma is still localized, function-preserving surgery is performed. In these cases, the possibility of instituting adjuvant chemotherapy with an active treatment regimen may be taken into account depending on the condition of the patient and the tumor. Patients with surgically resectable tumors are given 1-2 cycles of induction chemotherapy. Cases who respond to the induction chemotherapy are subsequently given concurrent chemoradiotherapy. Residual lymph nodes in the neck are removed surgically. The cases who do not respond to the induction chemotherapy are treated with radical surgery. Patients with unresectable carcinoma are given concurrent chemoradiotherapy because local treatment should be performed in such patients as early as possible. In principle, concurrent regimens should be supplemented with adjuvant chemotherapy in all cases. This is particularly required for those with advanced N-stage patients.

Adjuvant chemotherapy in head and neck cancer

An overview is presented of 23 trials of adjuvant chemotherapy in squamous cell carcinoma of the head and neck. These were reviewed from the point of view of design of the trial, analysis of survival, response rates, meta-analysis, site of failure, toxicity and cost. The minimal increase in survival that could be detected ranged from 11 to 51%, with a median of 25%. No trial was big enough to detect the likely increase of survival, which is 5%. Many trials excluded some eligible patients before randomisation, the proportion being 21% in those series with details. A further 9% of treated patients were excluded from analysis. A response rate in four induction studies of 47% equated with a 6% increase in cancer mortality. Meta-analysis showed an insignificant overall improvement in cancer mortality of 0.5%. Induction chemotherapy, synchronous chemotherapy and induction/maintenance chemotherapy did not affect cancer mortality whereas synchronous/maintenance therapy did. Cisplatinum, methotrexate, bleomycin, 5-FU and a variety of other regimens did not affect the death rate from cancer, but the combination of VBM significantly increased it. Neither single agent nor combination chemotherapy produced a significant reduction of cancer deaths. The rate of locoregional failure was significantly lower in the treated arms, whereas the metastatic rate was similar in both arms. Only three papers gave full details of toxicity with grading: these showed a high toxicity rate. The mortality rate from chemotherapy in nine series averaged 6.5%.

Chemosensitivity of squamous cell carcinoma grown in implantable chambers

This study was motivated by the need to develop new methods to predict tumor response to chemotherapeutic agents. Using implantable cell-growth chambers, squamous carcinoma cells from head and neck tumors were xenografted into the peritoneal cavity of immunocompetent rats. Animals were divided into control and treatment groups. The treatment groups received intravenous cisplatin (CDDP) or 5-fluorouracil (5-FU) v normal saline solution for the control. Animals from each group were randomly selected and killed on days 3, 5, and 7 postimplantation. The chambers were retrieved, the media aspirated, and cells counted. Exponential growth curves were derived for the control and treatment groups. Statistically significant growth inhibition was observed for both treatment arms, compared with controls. This method of chemosensitivity testing proved to be inexpensive and reliable, and demonstrated tumor cell killing by 5-FU and CDDP.