Spontaneous regression of recurrent hepatocellular carcinoma after TAE: possible mechanisms of immune mediation

Abstract

We report findings in a 76-year-old man who underwent a lateral segmentectomy of the liver for hepatocellular carcinoma in July 1996. In July 1997, transarterial embolization (TAE) was performed for recurrent tumors in the remnant liver. Augmentation of the tumors and an increase in protein induced by vitamin K absence or antagonist (PIVKA)-II level were noted in October 1997, and, although we recommended TAE again, the patient and his family refused further treatment. Subsequently, the patient was only observed, and, except for a small lesion that was probably a scar, no tumors were noted on image examinations in November 1998, and the PIVKA-II level had returned to a normal value at this time. Two years after the regression, the tumors appeared to be in complete spontaneous remission. This patient had no history indicative of ischemic necrosis, and levels of cellular surface markers for natural killer (NK) cells and NK cell activity showed high values, which suggested that tumor immunity was activated by some, unknown, mechanism.

Spontaneous regression of recurrent squamous cell carcinoma of the tongue

“…Nakai et al 8 reported elevated natural killer (NK) cell activity in a patient showing spontaneous regression of recurrent hepatocellular carcinoma, and they suggested that NK cells could influence regression by the nonspecific injury of tumor cells without either sensitization by antigens or the participation of a major histocompatibility complex. However, we did not observe an elevated level of NK cell activity.…”

Spontaneous Regression of Recurred Hepatocellular Carcinoma with Multiple Lung Metastases

“…4 Spontaneous regression has been reported in a variety of malignant cancers, including HCC, but this phenomenon is more frequently reported in neuroblastoma, malignant melanoma, and cancer of the kidney 4,[8][9][10][11] Various mechanisms have been proposed to explain spontaneous regression of HCC, with the most common being ischemic injury. 5,9 Biological factors, herbal medicines, immunological variations, high fever, reduction of nutrients necessary for tumor growth, blood transfusion, surgical trauma, vascular injury, cytokines, and endocrine factors have also been suggested to explain spontaneous regression, 6,[9][10][11][12][13] but none of the proposed mechanisms satisfactorily explain spontaneous regression of HCC.…”

“…Only approximately 50 cases have been reported to date. 5,6 We report a case of a 75-year-old woman who showed spontaneous regression of multiple pulmonary metastases of HCC.…”