Detection of melanoma seeding during surgical procedures--an RT-PCR based model

Does surgical resection of hepatocellular carcinoma accelerate cancer dissemination

AIM: This study was to investigate whether surgery could increase cancer dissemination and postoperative recurrence in patients with hepatocellular carcinoma (HCC) by detection of human αfetoprotein messenger RNA (hAFP mRNA). hAFP mRNA in the peripheral blood of patients with HCC has been considered as a surrogate marker for circulating tumor cells.

METHODS: Eighty-one consecutive patients who underwent curative resection for HCC entered this prospective cohort study. We examined hAFP mRNA from the peripheral blood obtained preoperatively, perioperatively, and postoperatively to correlate the prognosis after curative resections from HCC patients and from the control subjects. Detection of hAFP mRNA by reverse transcriptase and polymerase chain reaction amplification (RT-PCR) was performed with primers specifically. The relations between the clinical variables (age, sex, associated liver cirrhosis, hepatitis B virus infection, hepatitis C virus infection, serum α-fetoprotein and Child-Pugh class), the histological variables (size, capsule, vascular permeation, grade of differentiation, and daughter nodules), hAFP mRNA in peripheral blood of 3 different sessions, and postoperative course (recurrence, and recurrence related death) were analysed.

RESULTS: No hAFP mRNA was detected in control group subjects. Twenty-two (27%), 24 (30%) and 19 (23%) of 81 HCC patients had hAFP mRNA positivity in the preoperative, perioperative and postoperative peripheral blood. The preoperative presence did not influence the risk of HCC recurrence (55% vs 41%, P = 0.280). In contrast, patients with postoperative presence had a significantly higher recurrence (90% vs 31%, P < 0.001; odds ratio 19.2; 95% confidence interval: 4.0-91.7). In the multivariate analysis by COX proportional hazards model, postoperative positivity had a significant influence on recurrence (P = 0.067) and recurrence related mortality (P = 0.017). Whereas, the perioperative positivity of hAFP mRNA did not increase HCC recurrence (58% vs.39%, P = 0.093). The correlation between perioperative hAFP mRNA positivity and recurrence related mortality had no statistical significance (P = 0.836).

CONCLUSION: From our study, perioperative detection of hAFP mRNA in peripheral blood of patients has no clinical relevance and significant role in the prediction of HCC recurrence. Surgical resection itself may not accelerate cancer dissemination and does not increase postoperative recurrence significantly either.

Tumor doubling time of cutaneous melanoma and its metastasis

Tumor doubling time, estimated using clinical data, is one factor used to determine who will benefit from surgery for patients with pulmonary metastatic melanoma. Reported herein are the tumor doubling times of four primary cutaneous melanomas in which the diagnosis of melanoma had been delayed, and their metastases (3 of 4). The median/mean tumor doubling times for primary melanoma and metastatic melanoma was 94/144 days (range 50-377) and 33/64 days (range 8-212), respectively. By paired t test, metastatic tumor doubling time was significantly faster than primary tumor doubling time (P = 0.01). Extrapolating the growth curves of metastatic melanoma to the point of onset of metastasis revealed that dissemination of tumor cells occurred well before first clinical presentation and symptoms in two cases, and in one case, during the interval between clinical presentation and complete excision of the primary. At the opposite pole, extrapolated growth curves for slow tumor doubling time melanoma demonstrated that long-term follow up (>10 years) is required to determine whether patients have been cured of melanoma or not. Overall, these estimates of melanoma tumor doubling time validate the concept of tumor progression, reinforce the tenet of early detection and curative excision, and can explain the phenomenon of late onset of metastases, respectively.