Kato T, Suetake T, Tabata N, Takahashi K, Tagami H
Department of Dermatology, Tohoku University School of Medicine, Tohoku Koseinenkin General Hospital, Sendai, Japan.
Int J Dermatol. 1999 Jul;38(7):515-9. doi: 10.1046/j.1365-4362.1999.00736.x.
The plantar surface is one of the commonest sites of malignant melanoma in the Japanese; however, the biological behavior is not sufficiently clarified, because of the paucity of long-term studies. We attempted an epidemiologic survey of the cases of plantar melanoma treated in our institute to study the survival rate in the recent period.
Of the 207 cases of malignant melanoma observed over the past 28 years, 62 patients were diagnosed as having plantar melanoma. The proportion of plantar melanoma to all melanomas, the sex and age of the patients, and the histologic type, stage, and prognosis were evaluated by comparing those registered in the first half (1969-1982) and the second half (1983-1996) of the period.
The proportions of plantar melanoma in the first and second half periods were 31% (28 out of 90) and 29% (34 out of 117), respectively. No sex difference in the patients was observed. The mean age of the patients was 67 years. Fifty-one lesions were histologically proven to be acral lentiginous melanoma (ALM), two were superficial spreading melanoma (SSM), and nine were nodular melanoma (NM). Of the nine NMs, eight were registered in the second half period. The heel was affected in 33 (53%), the metatarsal regions in nine (14%), the toes in six (10%), and the arch areas in 14 (23%). The proportion of the weight-bearing areas, including the heel, metatarsal areas, and toes, decreased in the second half period. A comparison of the stages of plantar melanoma showed that, in the first half period, there were 18% of patients with stage IV disease in contrast to none in the second half period. Conversely, the proportion of stage I and II disease was 50% in the second half period, whereas it was only 39% in the first half period. The 5-year survival rates in the first and second half periods were 56% and 71%, respectively.
The prognosis of plantar melanoma has improved recently at our institute. The possible explanation for a trend to better survival in the second half period may be related to a decrease in stage IV disease as well as to an increase in the frequency of diagnosis of early stage disease.
足底是日本人恶性黑色素瘤最常见的发病部位之一；然而，由于长期研究较少，其生物学行为尚未得到充分阐明。我们对本院治疗的足底黑色素瘤病例进行了一项流行病学调查，以研究近期的生存率。
在过去28年观察到的207例恶性黑色素瘤病例中，62例被诊断为足底黑色素瘤。通过比较该时期前半段（1969 - 1982年）和后半段（1983 - 1996年）登记的病例，评估足底黑色素瘤在所有黑色素瘤中的比例、患者的性别和年龄、组织学类型、分期及预后。
前半段和后半段足底黑色素瘤的比例分别为31%（90例中的28例）和29%（117例中的34例）。未观察到患者的性别差异。患者的平均年龄为67岁。51个病灶经组织学证实为肢端雀斑样黑色素瘤（ALM）型，2个为浅表扩散性黑色素瘤（SSM）型，9个为结节性黑色素瘤（NM）型。在9例NM型中，8例登记于后半段。足跟受累33例（53%），跖骨区域9例（14%），足趾6例（10%），足弓区域14例（23%）。后半段包括足跟、跖骨区域和足趾的负重区域比例下降。足底黑色素瘤分期的比较显示，前半段有18%的患者为IV期疾病，而后半段无IV期患者。相反，后半段I期和II期疾病的比例为50%，而前半段仅为39%。前半段和后半段的5年生存率分别为56%和71%。
本院近期足底黑色素瘤的预后有所改善。后半段生存率提高趋势的可能原因可能与IV期疾病减少以及早期疾病诊断频率增加有关。
