Aquilina J W, McKinney L, Pacelli A, Richman L K, Waters D J, Thompson I, Burghardt W F, Bostwick D G
Mayo Clinic, Rochester, Minnesota 55905, USA.
Prostate. 1998 Aug 1;36(3):189-93. doi: 10.1002/(sici)1097-0045(19980801)36:3<189::aid-pros7>3.0.co;2-c.
High grade prostatic intraepithelial neoplasia (PIN) is the most likely precursor of human prostate cancer and is commonly found in men undergoing prostatic needle biopsy for suspected cancer. Recent work has demonstrated that pet dogs, like humans, develop PIN spontaneously and in association with prostate cancer. Pet dogs are the most domesticated animal, sharing the habitat and oftentimes the diet of their owners. If PIN and prostate cancer are strongly related to environmental factors, then the prevalence of these findings might differ in a population of dogs such as military working dogs which is not exposed to the habitat and diet of humans. In this study, we determined the prevalence of PIN in prostates of aged military working dogs with and without prostatic adenocarcinoma.
Cases were selected from the military working dog slide and tissue archive at the Armed Forces Institute of Pathology, Washington, DC. The most recent 329 necropsies (1991 to 1996) were examined histologically by multiple reviewers; of these, 199 dogs (60%) were found to have evaluable prostatic tissue. In addition, the most recent 50 necropsies (1958 to 1996) with the diagnosis of prostatic cancer were examined, of which 25 cases (50%) were found to have evaluable prostatic adenocarcinoma. In most cases, a single large transverse section of prostatic tissue was available for review. Medical records for each dog were reviewed independently, and age, clinical history, indications for euthanasia, and other health problems were recorded.
High grade PIN was identified in 3% of dogs (6 of 199 dogs) without prostate cancer. A total of 50.8% of dogs in this study group (101 of 199 dogs) were known to be sexually intact, 26.7% of dogs (53 of 199 dogs) were castrated, and the status of the remaining 22.6% of dogs (45 of 199 dogs) was unknown. High grade PIN was present in 18 of 25 dogs (72%) with prostatic adenocarcinoma. Of these cases, 11 dogs (44%) were castrated, 4 dogs (16%) were intact, and the status of 10 dogs (40%) dogs was unknown. Gleason scores ranged from 6 to 10, with a mean of 8.4 and a median of 8.
High grade PIN is present in a small but substantial number (3%) of military working dogs. Of military working dogs with prostatic adenocarcinoma, 72% had high grade PIN. The true prevalence in each of these cohorts is likely to be higher given the sampling variation inherent in evaluating a single random histologic section. Aged male dogs seem to have substantial clinical utility as an animal model for prostatic carcinogenesis. We recommend that serial sectioning and total embedding of the prostate should be used to more thoroughly characterize premalignant and malignant diseases in aged military working dogs. This method will provide important data to determine whether a model of spontaneous PIN in elderly dogs may have clinical utility in developing strategies directed toward preventing and treating prostate.
高级别前列腺上皮内瘤变（PIN）是人类前列腺癌最可能的前体，常见于因疑似癌症而接受前列腺穿刺活检的男性。最近的研究表明，宠物狗与人类一样，会自发发生PIN，并与前列腺癌相关。宠物狗是最驯化的动物，与主人共享栖息地，饮食也往往相同。如果PIN和前列腺癌与环境因素密切相关，那么在未接触人类栖息地和饮食的军犬等犬类群体中，这些发现的患病率可能会有所不同。在本研究中，我们确定了患有和未患有前列腺腺癌的老年军犬前列腺中PIN的患病率。
病例选自华盛顿特区武装部队病理研究所的军犬玻片和组织档案。由多名评审员对最近的329例尸检（1991年至1996年）进行组织学检查；其中，199只狗（60%）的前列腺组织可评估。此外，对最近50例诊断为前列腺癌的尸检（1958年至1996年）进行了检查，其中25例（50%）的前列腺腺癌可评估。在大多数情况下，只有一个前列腺组织的大横切片可供检查。对每只狗的病历进行独立审查，并记录年龄、临床病史、安乐死指征和其他健康问题。
在没有前列腺癌的狗中，3%（199只狗中的6只）发现有高级别PIN。该研究组中共有50.8%的狗（199只狗中的101只）已知具有完整的性功能，26.7%的狗（199只狗中的53只）已绝育，其余22.6%的狗（199只狗中的45只）的情况未知。在患有前列腺腺癌的25只狗中，18只（72%）有高级别PIN。在这些病例中，11只狗（44%）已绝育，4只狗（16%）具有完整的性功能，10只狗（40%）的情况未知。Gleason评分范围为6至10，平均为8.4，中位数为8。
高级别PIN在一小部分但数量可观（3%）的军犬中存在。在患有前列腺腺癌的军犬中，72%有高级别PIN。考虑到评估单个随机组织切片固有的抽样差异，这些队列中每一个的真实患病率可能更高。老年雄性狗作为前列腺癌发生的动物模型似乎具有很大的临床应用价值。我们建议对前列腺进行连续切片和整体包埋，以更全面地描述老年军犬的癌前和恶性疾病。这种方法将提供重要数据，以确定老年狗自发PIN模型在制定前列腺预防和治疗策略方面是否具有临床应用价值。
