Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential

Metastatic human HCC model is needed for the studies on mechanism and interven tion of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of hu man HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metasta sis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesio nmolecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis, antisense approach, metallopro teinase inhibitor, differentiation inducer, etc. It is concluded that the establ ishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vivo and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.

Artifact-resistant power-efficient design of finger-ring plethysmographic sensors

A miniaturized, telemetric, photoplethysmograph (PPG) sensor for long-term, continuous monitoring is presented in this paper. The sensor, called a "ring sensor," is attached to a finger base for monitoring beat-to-beat pulsation, and the data is sent to a host computer via a radio-frequency transmitter. Two major design issues are addressed: one is to minimize motion artifact and the other is to minimize the consumption of battery power. An efficient double ring design is developed to lower the influence of external force, acceleration, and ambient light, and to hold the sensor gently and securely on the skin, so that the circulation at the finger may not be obstructed. Total power consumption is analyzed in relation to characteristics of individual components, sampling rate, and CPU clock speed. Optimal operating conditions are obtained for minimizing the power budget. A prototype ring sensor is designed and built based on the power budget analysis and the artifact-resistive attachment method. It is verified through experiments that the ring sensor is resistant to interfering forces and acceleration acting on the ring body. Benchmarking tests with FDA-approved PPG and electrocardiogram reveal that the ring sensor is comparable to those devices in detecting beat-to-beat pulsation despite disturbances.

Experience of 1000 patients who underwent hepatectomy for small hepatocellular carcinoma

BACKGROUND

Recently, the implementation of screening programs using alpha-fetoprotein (AFP) and ultrasonography in high risk populations has identified increasing numbers of patients with small hepatocellular carcinoma (small HCC). The aim of this study was to summarize the authors' experience in patients who underwent hepatectomy for small HCC and the factors that influence or improve long term survival.

METHODS

The study included 1000 patients who underwent hepatectomy for small HCC (< or = 5 cm) and compared them with 1366 patients who underwent hepatectomy for large HCC (> 5 cm) during the same period. A Cox proportional-hazards model was used for multivariate analysis of prognostic factors.

RESULTS

Comparison between patients with small HCC (n = 1000 patients) and patients with large HCC (n = 1366 patients) revealed that those with small HCC had a higher resection rate (93.6% [1000 of 1068 patients] vs. 55.7% [1366 of 2451 patients]; P < 0.01), a higher curative resection rate (80.5% [805 of 1000 patients] vs. 60.7% [829 of 1366 patients]; P < 0.01), a lower operative mortality rate (1.5% [15 of 1000 patients] vs. 3.7% [50 of 1366 patients]; P < 0.01), better differentiation of tumor cells (Edmondson Grade 3-4; 14.9% vs. 20.1%; P < 0.01), a higher incidence of single nodule tumors (82.6% vs. 64.4%; P < 0.01), a higher proportion of well encapsulated tumors (73.3% vs. 46.3%; P < 0.01), a lower incidence of tumor emboli in the portal vein (4.9% vs. 20.8%; P < 0.01), and higher survival rates after undergoing resection (5 years: 62.7% vs. 37.1%; P < 0.01; 10 years: 46.3% vs. 29.2%; P < 0.01). No significant difference was found between survival after undergoing minor resection (n = 949 patients) or lobectomy (n = 51 patients) in patients with small HCC (P > 0.05). Reresection for subclinical recurrence or solitary pulmonary metastasis after small HCC resection was undertaken in 84 patients.

CONCLUSIONS

Resection is still the modality of first choice for the treatment of patients with small HCC. Minor resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality, and reresection for subclinical recurrence or solitary pulmonary metastasis was important approach to prolonging survival further.

Experience of 1000 patients who underwent hepatectomy for small hepatocellular carcinoma

BACKGROUND

Recently, the implementation of screening programs using alpha-fetoprotein (AFP) and ultrasonography in high risk populations has identified increasing numbers of patients with small hepatocellular carcinoma (small HCC). The aim of this study was to summarize the authors' experience in patients who underwent hepatectomy for small HCC and the factors that influence or improve long term survival.

METHODS

The study included 1000 patients who underwent hepatectomy for small HCC (< or = 5 cm) and compared them with 1366 patients who underwent hepatectomy for large HCC (> 5 cm) during the same period. A Cox proportional-hazards model was used for multivariate analysis of prognostic factors.

RESULTS

Comparison between patients with small HCC (n = 1000 patients) and patients with large HCC (n = 1366 patients) revealed that those with small HCC had a higher resection rate (93.6% [1000 of 1068 patients] vs. 55.7% [1366 of 2451 patients]; P < 0.01), a higher curative resection rate (80.5% [805 of 1000 patients] vs. 60.7% [829 of 1366 patients]; P < 0.01), a lower operative mortality rate (1.5% [15 of 1000 patients] vs. 3.7% [50 of 1366 patients]; P < 0.01), better differentiation of tumor cells (Edmondson Grade 3-4; 14.9% vs. 20.1%; P < 0.01), a higher incidence of single nodule tumors (82.6% vs. 64.4%; P < 0.01), a higher proportion of well encapsulated tumors (73.3% vs. 46.3%; P < 0.01), a lower incidence of tumor emboli in the portal vein (4.9% vs. 20.8%; P < 0.01), and higher survival rates after undergoing resection (5 years: 62.7% vs. 37.1%; P < 0.01; 10 years: 46.3% vs. 29.2%; P < 0.01). No significant difference was found between survival after undergoing minor resection (n = 949 patients) or lobectomy (n = 51 patients) in patients with small HCC (P > 0.05). Reresection for subclinical recurrence or solitary pulmonary metastasis after small HCC resection was undertaken in 84 patients.

CONCLUSIONS

Resection is still the modality of first choice for the treatment of patients with small HCC. Minor resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality, and reresection for subclinical recurrence or solitary pulmonary metastasis was important approach to prolonging survival further.

Experience of 1000 patients who underwent hepatectomy for small hepatocellular carcinoma

BACKGROUND

Recently, the implementation of screening programs using alpha-fetoprotein (AFP) and ultrasonography in high risk populations has identified increasing numbers of patients with small hepatocellular carcinoma (small HCC). The aim of this study was to summarize the authors' experience in patients who underwent hepatectomy for small HCC and the factors that influence or improve long term survival.

METHODS

The study included 1000 patients who underwent hepatectomy for small HCC (< or = 5 cm) and compared them with 1366 patients who underwent hepatectomy for large HCC (> 5 cm) during the same period. A Cox proportional-hazards model was used for multivariate analysis of prognostic factors.

RESULTS

Comparison between patients with small HCC (n = 1000 patients) and patients with large HCC (n = 1366 patients) revealed that those with small HCC had a higher resection rate (93.6% [1000 of 1068 patients] vs. 55.7% [1366 of 2451 patients]; P < 0.01), a higher curative resection rate (80.5% [805 of 1000 patients] vs. 60.7% [829 of 1366 patients]; P < 0.01), a lower operative mortality rate (1.5% [15 of 1000 patients] vs. 3.7% [50 of 1366 patients]; P < 0.01), better differentiation of tumor cells (Edmondson Grade 3-4; 14.9% vs. 20.1%; P < 0.01), a higher incidence of single nodule tumors (82.6% vs. 64.4%; P < 0.01), a higher proportion of well encapsulated tumors (73.3% vs. 46.3%; P < 0.01), a lower incidence of tumor emboli in the portal vein (4.9% vs. 20.8%; P < 0.01), and higher survival rates after undergoing resection (5 years: 62.7% vs. 37.1%; P < 0.01; 10 years: 46.3% vs. 29.2%; P < 0.01). No significant difference was found between survival after undergoing minor resection (n = 949 patients) or lobectomy (n = 51 patients) in patients with small HCC (P > 0.05). Reresection for subclinical recurrence or solitary pulmonary metastasis after small HCC resection was undertaken in 84 patients.

CONCLUSIONS

Resection is still the modality of first choice for the treatment of patients with small HCC. Minor resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality, and reresection for subclinical recurrence or solitary pulmonary metastasis was important approach to prolonging survival further.

The development of efficient protocols for the palladium-catalyzed cyclization reactions of secondary amides and carbamates

[formula: see text] With the proper choice of palladium catalyst, ligand, and base, five-, six-, and seven-membered rings are formed efficiently from secondary amide or secondary carbamate precursors, offering significant improvements to currently existing methodology.

Seasonal and diurnal variations of ocular pressure in ocular hypertensive subjects in Pakistan

BACKGROUND

Studies have been shown that intraocular pressure (IOP) shows a diurnal variation in ocular hypertensive subjects, but the amount of change differs from study to study. In recent years it has been noted that intraocular pressure is a dynamic function and is subjected to many influences both acutely and over the long term. The variability in the results may be due to negligence of factors that can affect IOP. Moreover, seasonal variations in the ocular hypertensive subjects have never been described. After placing control on those factors that can affect IOP, this study investigated seasonal and diurnal variations in IOP of ocular hypertensive subjects.

PATIENTS AND METHODS

IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in 91 ocular hypertensive male subjects. To see the diurnal changes, subjects were asked to stay in the hospital for 24 hours.

RESULTS

The average IOP in the winter months was higher than those in spring, summer, and autumn. The IOP difference between winter and summer was (mean +/- sem) 2.9 +/- 0.9 mmHg (p < 0.001). The peak of mean IOP in diurnal variation curve (25.7 +/- 1.2 mmHg) appeared in the morning when the subjects had just awaken. The mean diurnal variation was found to be 4.2 +/- 0.6 mmHg (p < 0.001).

CONCLUSIONS

This study confirms that seasons influence IOP and it shows diurnal variations. As compared to other nations, diurnal variations in ocular hypertensive subjects seem to be somewhat less in Pakistan. Knowledge of the seasonal and diurnal variations in IOP may help glaucoma screeners.

A possible hydrolysis mechanism of beta-naphthyl acetate catalyzed by antibodies

The mechanism of ester hydrolysis has been extensively studied; however, the precise function of active-site residues in promoting catalysis is unclear. We describe here the structural models for the complex of a catalytic antibody Fv fragment with a phosphonate transition-state analogue, constructed by using gene cloning, sequencing and molecular modeling, mainly based on a known X-ray structure of a catalytic antibody. Hydrophobic and electrostatic analyses of the Fv/analog and Fv/substrate interaction suggest the hydrolysis mechanism: Tyr L91 and Tyr H97 play important roles to stabilize the beta-naphthyl group of hapten through pi-stack; His H35 donates a pair of free electrons at the atom NE2 to an active water and let it to be a partial hydroxide, which attacks the carbon atom of the carbonyl group of the substrate. Both His H35 and Arg L96 can form hydrogen bonds and stabilize the anionic tetrahedral intermediate formed during turnover. This mechanism emphasizes that an active water bridge may be formed during hydrolysis process.

An improved rapid method for selecting monoclonal antibodies with high catalytic activities

Monoclonal antibodies were raised against a beta-naphthyl phosphonate hapten (1) to elicit antibodies capable of catalyzing the hydrolysis of beta-naphthyl acetate (3). After cell fusion, potential catalytic antibody-producing hybridomas were selected, by use of a competitive inhibition assay on the basis of the binding activity for a short transition-state analogue (inhibitor 5), followed by use of high-performance liquid chromatography analysis for the hybridoma supernatants to screen the antibodies processing catalytic activities. It was shown that supernatants of 12 wells had high binding activity with inhibitor and of them, 7 had catalytic activities. After cloning by limiting dilution, we got two hybridoma clones producing monoclonal antibodies which catalyzed the hydrolysis of beta-naphthyl acetate. This combination of competitive inhibition assay with high-performance liquid chromatography analysis represents an improved rapid approach for the screening of potential catalytic antibodies and significantly increases the possibility of obtaining efficient catalytic monoclonal antibodies. Further study of the catalytic antibodies revealed significant rate enhancement (Kcat/K(uncat) approximately 10(6) and specificity.

Three decades' experience in surgery of hepatocellular carcinoma

In the author's institution, 2254 patients with hepatocellular carcinoma (HCC) have been treated during 1958-1994. The overall 5-year survival increased from 5.4% (1958-1970), to 11.9% (1971-1982), to 46.2% (1983-1984), which correlated well with the increasing proportion of small HCC in the series (2.6%, 12.1%, and 33.4%, respectively); with the increasing percentage of limited resection (3.1%, 32.2%, and 58.3%); with the increasing number of re-resections for recurrence (0, 27, and 114 patients); and with the increasing number of second stage resections (0, 5, and 67 patients). In our institution, surgical approaches that resulted in significantly prolonging survival included: small HCC resection, re-resection, and cytoreduction followed by sequential resection for initially unresectable HCC. Experience in these 3 aspects suggests: (a) Small HCCs are mainly found by screening using AFP and ultrasonography (US) in a high risk population, and limited resection is the best treatment in patients with compensated liver cirrhosis, the 5-year survival after resection being 62.9% (n = 549). (b) Postoperative monitoring using AFP/US every 2-3 months for 5-10 years after curative resection is needed to detect subclinical recurrence. Limited re-resection is indicated for liver recurrence less than 3 nodules, and lung lobectomy is of proven merit to prolong survival for solitary lung metastasis. Re-resection of subclinical recurrence has resulted in a 10-20% further increase in 5-year survival after curative resection. (c) Palliative surgery other than resection such as hepatic artery ligation (HAL) and cannulation with arterial infusion (HAI), cryosurgery, etc. are superior to palliative resection with residual cancer. (d) Cytoreduction and sequential resection have provided hope for localized unresectable HCC, particularly in the right cirrhotic liver. Multimodality combination treatments such as HAL+HAI+radioimmunotherapy/regional radiotherapy are acceptable cytoreductive therapies. Repeated transcatheter hepatic arterial chemoembolization (TACE) is an alternative nonsurgical approach. Sequential resection is important to eradicate residual cancer after cytoreduction. The 5-year survival of 72 patients with cytoreduction and sequential resection for initially unresectable HCC was 62.1% and resulted in improving 5-year survival in the entire series of unresectable HCC over the 3 periods from 0% to 7.4% to 25.7%, respectively. However, multicentric origin and tumor invasiveness are two major targets to be studied in the control of recurrence and metastasis.

Inhibitory effect of the angiogenesis inhibitor TNP-470 on tumor growth and metastasis in nude mice bearing human hepatocellular carcinoma

The antitumor and anti-metastatic effects of a potent angiogenesis inhibitor, O-(chloroacetyl-carbamoyl)fumagillol (TNP-470), was investigated in a highly metastatic model of human hepatocellular carcinoma-LCI-D20. Small pieces of LCI-D20 tumor tissue were implanted subcutaneously into the right axillary region of 24 nude mice; the mice were then randomized into two groups. To one group, TNP-470 30 mg/kg was given as a subcutaneous injection every other day from day 1 to day 15 and the mice were sacrificed on day 26. An antitumor effect of TNP-470 was clearly demonstrated by tumor weight (0.97 +/- 0.34 g compared to 2.04 +/- 0.34 g, P < 0.001) and alpha-Fetoprotein value (93 +/- 59 micrograms/L compared to 769 +/- 282 micrograms/L, P < 0.001). There was also an anti-metastatic effect of TNP-470. Lung metastases developed in only 1 of 12 mice in the treated group, while they developed in 6 of mice of the control group. No severe side-effect of TNP-470 was found in this study. In vitro study revealed that the purified hepatoma cells were insensitive to TNP-470 (the 50% inhibitory concentration was 43 micrograms/ml). These results suggest that the angiogenesis inhibitor TNP-470 has both strong antitumor and anti-metastatic effects on a human hepatocellular carcinoma model in nude mice.

Long-term results of surgery for small primary liver cancer in 514 adults

During 1958-1993, 2030 patients with pathologically proven primary liver cancer (PLC) were retrospectively reviewed. Comparison between small PLC (< or = 5 cm, n = 514) and large PLC (> 5 cm, n = 1516) revealed that small PLC had a higher resection rate (92.4% versus 49.1%), lower operative mortality (1.7% versus 5.2%), a higher percentage of single tumour nodules (78.0% versus 53.4%), a higher percentage of well encapsulated tumour (74.5% versus 35.8%) and higher survival rates after resection (5-year, 63.8% versus 36.6%; 10-year, 46.8% versus 28.5%). No significant difference was found between survival following limited resection (n = 440) and lobectomy (n = 34) in patients with small PLC. Re-resection of any subclinical recurrence or solitary pulmonary metastasis after small PLC resection was done in 70 cases. These results indicate that resection is still the modality of choice for treatment of small PLC; limited resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality; re-resection of subclinical recurrence was important to prolong survival further.

Cytoreduction and sequential resection for surgically verified unresectable hepatocellular carcinoma: evaluation with analysis of 72 patients

The poor prognosis of hepatocellular carcinoma (HCC) was partly a result of the majority of unresectable HCCs in clinical patients. Fortunately, with the progress of regional cancer therapies and multimodality treatment, some of the localized unresectable HCCs were converted to resectable ones. During the period 1960-1994, 72 of the 663 patients with surgically verified unresectable HCCs have been converted to resectable. Successful cytoreduction with median diameter reduced from 10 cm to 5 cm was mainly a result of the triple or double combination treatment with hepatic artery ligation, hepatic artery cannulation with infusion, radioimmunotherapy, and fractionated regional radiotherapy. The interval between the first operation and the sequential resection was 5 months. The operative mortality was 1.4% for sequential resection, and the 5-year survival was 62.1%. Analysis of factor influencing sequential resection rate revealed HCCs that were single nodule, well encapsulated, situated at right lobe or hepatic hilum, associated with micronodular cirrhosis, and treated with triple or double combination modalities had higher sequential resection rate as compared to their counterparts. Analysis of factors influencing survival after sequential resection revealed that HCCs with a solitary tumor confined in one lobe, without tumor embolus, and without residual cancer in specimen of sequential resection, had longer survival. It is suggested that localized unresectable, solitary, well encapsulated, right lobe or hilar HCC, associated with micronodular cirrhosis, will be good candidates for cytoreduction and sequential resection; and HCCs with unilateral involvement, without tumor embolus, and with complete necrosis of tumor after multimodality treatment favored better prognosis.

Secondary prevention of hepatocellular carcinoma

Two decades have gone by since the earlier trials of alpha-fetoprotein (AFP) screening for hepatocellular carcinoma (HCC) were conducted in Africa and China. It is accepted that early detection, diagnosis and treatment of HCC remains an important target to be achieved before a breakthrough appears on the primary prevention of HCC. In the present study, screening investigations were performed in a high risk population of HCC, defined as persons who had hepatitis, blood transfusions, a family history of HCC, and were hepatitis B virus carriers. Ultrasonography combined with AFP serosurvey was accepted as an effective screening procedure to detect small HCC. Early diagnosis of HCC was not difficult if tumour markers and medical imaging were combined. Early resection has been proven to prolong survival of patients with small HCC. Repeated intralesional ethanol injection is an alternative treatment to surgery, while transcatheter arterial embolization is a less effective alternative. Re-resection of subclinical recurrence after curative resection has proven of merit in prolonging survival even further. Resection of small HCC remains an important approach in getting long-term HCC survival and to improving 5-year survival rates. It is more effective than treatment of large HCC. Studies on the secondary prevention of HCC have stimulated research into tumour markers, the natural history and cellular origin of HCC and oncogenes. However, the issue of 'cost-effectiveness' remains to be evaluated.

Characteristics and prognosis of primary liver cancer in young patients in China

To investigate the clinicopathologic characteristics of primary liver cancer (PLC) in young adults, 77 patients aged 35 or younger were compared with 603 patients older than 35 years during the same period. In the young patients, PLC showed: (1) a low incidence detected at mass survey (young 15.6% vs older 28.7%, P < 0.05); (2) a low level of history of hepatitis (young 36.8% vs older 66.3%, P < 0.01); (3) a high incidence of positivity for hepatitis B surface antigen (HBsAg) (young 79.2% vs older 67.6%, P < 0.05); (4) a relatively low incidence of associated cirrhosis (young 64.9% vs older 90.7%, P < 0.01); (5) larger tumor size (PLC > 5 cm; young 87.0% vs older 73.0%, P < 0.01); and (6) a more advanced stage of the disease according to the TNM classification (stage III; young 29.9% vs older 18.2%, P < 0.05). It is suggested that hepatitis B virus (HBV) may play an important role in the development of PLC without associated liver cirrhosis in young patients. Close periodic surveillance of young adults who are positive for HBsAg is important to detect PLC at an early stage.

Multimodality treatment in advanced primary liver cancer

This paper reports the long-term results of multimodality treatment in 1639 patients with pathologically proven primary liver cancer (PLC) over the past three decades. In this series, patients in subclinical stage constituted 23.9% (391/1639), moderate stage 63.0% (1032/1639), and late stage 13.2% (216/1639). There were 381 patients (23.2%) with small PLC (< = 5 cm). The PLC was coexistent with liver cirrhosis in 86.4% (1416/1639). The 5-year survival after resection of PLC was 45.5% for the whole series (n = 896), and 62.7% for patients with a tumor < = 5 cm (n = 345). The 5-year survival after hepatic artery ligation (HAL) and hepatic artery infusion (HAI) (n = 124) was 18.1%, while the 5-year survival after palliative resection (n = 175) was 12.5%. The 5-year survival of 40 patients receiving second-look resection after cytoreduction therapy was 68.4%. Cryosurgery was performed on 107 PLC patients, the 5-year survival being 22.0% for the whole series, and 48.8% for the 32 patients with small PLC. The 5-year recurrence rate after resection was 55.3%. The 5-year survival after reoperation for recurring tumor (n = 90) was 40.8%. It is suggested that surgery remains the modality of choice, and it plays a more important role in the treatment of PLC. The results of palliative surgery (HAL + HAI) seem better than those of palliative resection; combined multimodality treatment and second-look resection, and new surgical techniques might offer hope for unresectable advanced PLC.

Observation of changes in peripheral T-lymphocyte subsets by flow cytometry in patients with liver cancer treated with radioimmunotherapy

An analysis of lymphocyte subsets was performed in 24 patients with surgically verified unresectable hepatocellular carcinoma (HCC). In all cases, the hepatic artery was cannulated and ligated and a single dose of 131I-Hepama-1 monoclonal antibody (MAb) was infused through a hepatic artery catheter. Blood samples were obtained before infusion and 1 month post-infusion. The results indicated that the CD3+ T-cells (pan T-cells) were normal, whereas the CD4+ T-cells (T-helper/inducer cells) decreased and the CD8+ T-cells (T-suppressor/cytotoxic cells) increased significantly in comparison with the control group. So the CD4+:CD8+ ratio declined markedly. One month post-radioimmunotherapy (RIT), the T-cell subsets did not change, but CD4+, CD8+ and the CD4+:CD8+ ratio differed significantly between patients with and without sequential resection. The changes in the T-cell subsets were closely related to tumour capsule status and the human anti-murine antibody (HAMA) response, but no relationship was found between the tumour and administration of a moderate dose of radioimmunoconjugate. Therefore, determination of changes in the T-lymphocyte subsets and the CD4+:CD8+ ratio could be used as clinical and prognostic indicators in patients who have received RIT. Furthermore, RIT did not affect the distribution of T-cell subsets in patients with HCC.

Treatment of unresectable primary liver cancer: with reference to cytoreduction and sequential resection

Unquestionably, progress has been made in the early detection and early treatment of primary liver cancers (PLCs), although most remain unresectable, mainly because the cancer is advanced and coexists with liver cirrhosis, particularly in Oriental patients. Thanks to the progress of regional cancer therapy, a multidisciplinary approach, and changing concepts about surgical oncology, it has been proved that some unresectable but not far advanced PLCs are potentially convertible to being resectable, particularly those cancers confined to the right lobe of a cirrhotic liver. A retrospective analysis of 571 unresectable PLCs revealed the following: (1) There was an increase in 5-year survivals in the series, from 0% during the 1960s (n = 61), to 4.8% during the 1970s (n = 163), to 21.2% during the 1980s (n = 347). It might be a result of the increase in double- or triple-modality treatments in these series (from 9.8%, to 19.6%, to 70.3%, respectively) and in the sequential resection rate after cytoreduction (from 0%, to 2.5%, to 14.7%). (2) The combination of hepatic artery ligation, hepatic artery cannulation and infusion, and intrahepatic arterial radioimmunotherapy has resulted in better shrinkage of the tumor, a higher sequential resection rate, and a higher 5-year survival (28.2%). (3) Of the 55 patients who had initially unresectable PLCs and yielded "cytoreduction and sequential resection," the 5-year survival was 58.5%. It is concluded that cytoreduction and sequential resection might be an important approach to improving the prognosis of patients with unresectable PLCs.

Recurrence after resection of alpha-fetoprotein-positive hepatocellular carcinoma

The long-term prognosis of surgery for hepatocellular carcinoma (HCC) is not yet satisfactory, the main reason being the high recurrence rate. The authors report the results of a long-term follow-up of 308 patients with HCC who became alpha-fetoprotein-(AFP)-negative after resection between 1975 and 1991. By March 1992, there was recurrence in 134 patients (43.5%). The 1-, 3-, 5- and 10-year recurrence rates were 9.2%, 38.8%, 54.9% and 85.0%, respectively. The 5-year survival rate was 49.7% for patients who had undergone a second hepatic resection (n = 48). Analysis of factors influencing postoperative recurrence indicated that patients subjected to mass survey, with a lower gamma-glutamyltransferase level, at an early stage of TNM classification, with a tumour of less than 5 cm, without tumour embolus, and with postoperative immunotherapy had a lower incidence of recurrence. It is concluded that the earlier the disease is diagnosed, the less the recurrence rate; adjuvant immunotherapy may reduce postoperative recurrence, and the early detection and resection of a recurrent tumour are important to prolonging survival further after curative resection of HCC.

Surgical treatment of recurrent hepatocellular carcinoma

During the last 16 years, radical resection was performed in 392 patients with hepatocellular carcinoma (HCC). Eight patients died within 30 days after resection. The other 384 patients were discharged from hospital and closely followed for 6 to 195 months. By December 1991, 185 patients had developed a recurrent tumor, the 1-, 3-, and 5-year recurrence rates being 15.0%, 45.4%, and 55.3%, respectively. Ninety of the 185 patients underwent reoperation, including second hepatic resection (65 cases), cryosurgery (8 cases), resection of lung metastasis (6 cases), hepatic artery ligation and infusion chemotherapy (2 cases), intratumor ethanol injection (3 cases), microwave coagulation plus intratumor ethanol injection (2 cases), and exploration (4 cases). The survival rate of these 90 patients was significantly better than that of 95 patients who were treated by other palliative methods, the 5-year survival rate being 63.4% as compared with 28.6% after the first resection (P < 0.01), and 40.8% vs. 2.2% after recurrence (P < 0.01), respectively. These results suggest that reoperation for recurrent HCC might be an important approach to prolonging survival further after hepatic resection.

Subclinical hepatocellular carcinoma: an analysis of 391 patients

Subclinical hepatocellular carcinoma (SCHCC) is defined as HCC without obvious HCC symptoms and signs. During 1958-1991, 391 patients with SCHCC were analyzed. In the entire series, 1) 67.3% was detected by natural population screening using alpha-fetoprotein (AFP) serosurvey, while the others were discovered by high-risk population screening or regular health checkup using AFP and/or ultrasonography (US); 2) AFP > 20 micrograms/L was found in 77.6% of patients; 3) serum hepatitis B surface antigen (HBsAg) was positive in 68.9%; 4) associated liver cirrhosis occurred in 89.1%; 5) the median tumor size was 5 cm, and small HCC (< or = 5 cm) amounted to 61.1%; 6) resection was done in 81.4%, and limited resection was performed in the majority (71.3%); 7) re-resection for subclinical recurrence was done in 44 patients; and 8) cytoreduction and sequential resection was carried out in 13 patients with unresectable SCHCC. Comparison between SCHCC and clinical HCC (n = 1,251) revealed higher resectability (81.4% vs. 46.8%), lower operative mortality (1.9% vs. 6.0%), and higher 5-year survival (entire series: 50.7% vs. 20.6%; resection: 60.5% vs. 36.8%). It is concluded that the study of SCHCC has resulted in marked improvement of ultimate outcome of HCC; screening in high-risk populations using AFP and/or US, limited resection, and re-resection for subclinical recurrence are some of the key features.