Radiotherapy of double primary esophageal carcinoma

INTRODUCTION

Double primary esophageal carcinoma is defined as having two foci of squamous cell cancer simultaneously or consecutively developing in different sites of esophagus. This rare disease appears mostly in the literature as case reports[1-4], reports about its treatment are even more infrequent. Here we present our experiences of radiation therapy in 37 patients with this disease and focus the discussion on the optimum method of treatment and complications.

MATERIALS AND METHODS

Materials

Criteria for diagnosing double primary esophageal carcinoma: ① typical findings seen in barium esophagograms, ② two separate lesions spaced ≥ 4 cm apart from each other, with intervening normal mucosa, ③ with endoscopic, pathologic or cytological proof of malignancy, ④ hypopharyngeal or gastric cardia lesions are excluded.

There were 25 males and 12 females, aged 41-80 years, with a peak range of 51-70 years (67.6% ). Thirteen of 37 ( 35.1% ) had supraclavicular lymph node metastasis before or during the treatment, 35.1% of patients had lesions in the upper-middle and 64.9% were in the upper-lower segments. The intervening normal mucosa varied from 4 to 13 cm. Length of both lesions was ≥ 5.0 cm in 12 patients, ≥ 5.0 cm in one and < 5.0 cm in the other in 21 cases, both lesions < 5.0 cm in four. The double primaries: developed simultaneously or within 6 months in 48.6%, those developed beyond 6 months to 3 years in 35.1% and over three years in 16.2%. The longest interval of developing a second primary was 12 years and 8 months. All these were squamous cell carcinoma, among them, 33 were proved by pathology or cytology and 4 by pathology singly.

Treatment

Thirty-three patients received radiation therapy (separate field irradiation) for both lesions and 4 patients refused to have irradiation of the second lesion because of psychological reasons. Among them, two-thirds were treated by rolling technique, and one-third by antero-posterior irradi ation, at 30-40 Gy/wk. The rest of the dose was delivered by two posterior oblique technique. In 59.5%, each individual lesion received a curative dose of 60GY-70Gy/30F-35F/6 wk-7 wk and 40.5% received a palliative dose ( ≤ 40 Gy/20 F/4 wk) or with one lesion left untreated. Statistical calculation was done by Chi-square test.

RESULTS

The 1, 3 and 5-year survival rates were 27%, 5% and 0%, different from those with single lesion (38%, 13% and 8.4%) in 3798 patient s treated in our hospital but with no statistical significance (P > 0.05 , χ² = 1.854, χ² = 2.1). The failure due to metastasis was very high, giving no 5-year survivor.

The 1- and 3-year survival rates of patients who received curative doses were 27.2% and 9.1% and 26.7% and 0%; for those who received palliative doses.Only those with two lesions irradiated were able to survive more than one year, even with absence of supraclavicular lymph node metastasis, the curative group had no 5-year survival.

In the present series, 62.1% failed by local recurrence, 10.8% by pulmonary radiation injury and 29.8% by distant metastasis.

DISCUSSION

The 1-, 3- and 5-year survival rates of double primary esophageal cancer trea ted with radiation therapy were 27%, 5% and 0% as against 38%, 13% and 8.4% with only one lesion, without statistical significance ( P > 0.05 ).The 1- and 3-year survival rates of curative dose were 27.3% and 9% vs 26.7% and 0% of those given palliative dose. The 1- and 3-year survival rates of those having no supraclavicular lymph note metastasis were 38.5% and 15.4%.

In debilitated or those who already had supraclavicular node metastasis, palliative dose would give symptomatic relief and prolongation of life. But in cases in which one of the two lesions was left untreated, none lived for over one year.

To improve its prognosis, early diagnosis is essential. During the follow-up examination of post-irradiated esophageal cancer patients, care should be directed not to miss a second primary focus. About 83.3% of the second primary would appear within 3 years after the detection of the first primary focus.