Download the ESMO 2012 Abstract Book - Oxford Journals

Conclusions: AMPK and ACC activation showed a weak correlation in primary and
metastastatic tumors, possibly due to the small number of patients and the higher
heterogeneity of the metastatic tissue. The opportunity to use these biomarkers to
predict a necrotic response to bevacizumab treatment is under investigation.
Disclosure: All authors have declared no conflicts of interest.
619 DIFFERENTIAL ANTIGENIC EXPRESSION IN COLORECTAL
CANCER, MUCOSA ADJACENT TO COLORECTAL CANCER,
AND NORMAL COLORECTAL MUCOSA
A. Zwenger 1 , G. Grosman 2 , S. Demichellis 3 , A. Segal-Eiras 3 , M.V. Croce 3
1 Oncologia, Hospital Provincial Neuquen, Neuquen, ARGENTINA, 2 Patologia,
Hospital Provincial Neuquen, Neuquen, ARGENTINA, 3 Centre for Basic and
Applied Immunological Research, Faculty of Medical Sciences National University
of La Plata, La Plata, ARGENTINA
Introduction: Despite of an excellent oncologic surgery with broad normal tissue
margins, the mucosa next to the bed anastomosed is a frequent place of tumoral
recurrence on colorectal cancer. Objective: This study was performed to evaluate the
expression of mucins and carbohydrates associated antigens in normal mucosa
colorectal specimens (NMC), mucosa adjacent to colorectal cancer (MACCR) and
malignant colorectal tumour samples (CCR).
Methods: Ninety colorectal cancer tumour samples and their MACCR, and also 68
NMC were included. Monoclonal antibodies (MAbs) against the following antigens
were employed: anti-MUC1 (HMFG1), MUC2 (H-300) and MUC5AC (45M1),
anti-Tn (HB-Tn1), Lex (KM380), sLex (KM93), Ley (C70) and sLea (1116-N5-19-9).
An immunohistochemical approach following standard procedures was performed.
Statistical analysis: an univariate statistical analysis with Chi2 was applied.
Results: Malignant samples expressed MUC1 in 94% of cases, MUC2 in 52.4%,
MUC5AC in 14.3%, Tn in 41%, Lex in 74.4%, sLex in 66.7%, Ley in 91.8% and sLea
in 90.7%. Taking into account MUC2 and Ley expression, a positive correlation was
found between MACCR and CCR: MUC2, P = .0006 and Ley, P = .0008. In
malignant samples, MUC1 expression was increased compared to NMC (P = .04),
also this mucin was 22.2% higher in MACCR than NMC. The expression of sLex
and Ley was higher in CCR than NMC (179% and 33.6%, respectively). Expression
of most antigens showed an increased tendency from NMC to MACCR and CCR:
MUC1 (27.9%, 34.1% and 94%, respectively), Lex (60.9%, 30.5% and 74.4%,
respectively), sLex (23.9%, 16.9% and 66.7%, respectively), Ley (68.7%, 78.3% and
91.8%, respectively) and sLea (62.1%, 45.6% and 90.7%, respectively). On the other
hand, MUC5AC expression decreased in the mentioned sequence (51.5%, 20.7% and
14.3, respectively).
Conclusion: Our results may support the hypothesis that the MACCR could be an
intermediate point or “transitional zone” between NMC and CCR. Further studies
are needed in order to correlate these findings with clinical outcomes.
Disclosure: All authors have declared no conflicts of interest.
620 IMPACT OF THE INTERVAL BETWEEN SURGERY AND
ADJUVANT MFOLFOX6 ON SURVIVAL OF COLON CANCER
PATIENTS
J. Godinho Bexiga, F. Carneiro, D.S. Marques, N. Sousa, C. Faustino,
A. Raimundo, M. Machado, P. Ferreira, M. Fragoso
Medical Oncology, Portuguese Institute of Oncology of Oporto, Oporto,
PORTUGAL
Background: Adjuvant chemotherapy with the association of Oxaliplatin and
Fluoropyrimidines has shown to reduce recurrence risk and improve survival in stage
III colon cancer patients in comparison to Fluoropyrimidines alone. The ideal timing
for the start of adjuvant chemotherapy has not been defined. Our aim was to
determine the impact of the interval between surgery and the start of adjuvant
chemotherapy on survival of colon cancer patients.
Material and methods: Retrospective cohort study, in a Portuguese cancer centre, of
colon cancer (CC) patients treated with mFOLFOX6 in the adjuvant setting, from
Table: 621
Group
5-year
RFS HR [95% CI]
September 2004 till November 2009. Two groups of patients were defined according
to the timing of adjuvant chemotherapy (CT): ≤ 8weeks or >8 weeks after surgery.
Efficacy was evaluated by overall survival (OS) and disease-free survival (DFS).
Hazard ratios and 95% confidence intervals were calculated with the use of the Cox
proportional hazards model.
Results: Two hundred and seventy seven patients were treated with adjuvant
mFOLFOX6 and followed for a median time of 45 months. Median age was 62 years
(28-79); 57% were male and 77% had stage III CC. Median time to the start of CT
was 8 weeks (P25 = 7, P75 = 10). The group of patients that started CT > 8 weeks
after surgery was older (mean age: 62 vs 59 years, p = 0.001) and tended to
accomplish lower relative dose-intensity of Oxaliplatin and 5-Fluorouracil (69,5% vs
72% and 73% vs 76%, respectively; p > 0.05). There was a tendency to lower OS and
DFS in the group that started CT >8 weeks after surgery. At 3 years, the probability
of OS was 83% vs 90% (p = 0.118), and DFS: 75% vs 77% (p = 0.751). Multivariate
analysis showed that the interval between surgery and the start of adjuvant CT had
no impact in OS nor DFS.
Conclusions: Our data point to a tendency to better survival when CT is started
within 8 weeks of surgery, strengthening the need for a timely referral of
patients to adjuvant treatment. The small sample size and the short follow-up
might explain why we were unable to find statistical significance in this
association.
Disclosure: All authors have declared no conflicts of interest.
621 IS ADJUVANT CHEMOTHERAPY (CT) BENEFICIAL TO STAGE II
COLON CANCER (CC) WITH ELASTIC LAMINANL INVASION
(ELI)?
M. Yokota 1 , M. Kojima 2 , S. Nomura 3 , A. Koyama 1 , M. Sugito 1 , M. Ito 1 ,
A. Kobayashi 1 , Y. Nishizawa 1 , A. Ochiai 2 , N. Saito 1
1 Department of Gastrointestinal Oncology, Colorectal Surgery, National Cancer
Center Hospital East, Kashiwa, JAPAN, 2 Research Center for Innovative
Oncology, Pathology, National Cancer Center Hospital East, Kashiwa, JAPAN,
3 Research Center for Innovative Oncology, Clinical Trial Section, National Cancer
Center Hospital East, Kashiwa, JAPAN
Background: The peritoneal elastic lamina (PEL) is situated just under the visceral
peritoneum and invests intestine wall. We defined cases with tumor invasion beyond
the PEL as positive for ELI (ELI (+)). We have reported that PEL can be a useful
pathologic hallmark to classify the level of tumor invasion in CC, and represented as
an independent risk factor for recurrence free survival (RFS) for stage II CC (Kojima
et al. Am J Surg Pathol. 2010;34:1351-60). We evaluated the necessity of adjuvant CT
for stage II CC with ELI (+).
Methods: We screened a database of 436 patients (pts) who underwent curative
resection for pT3 and pT4a CC in our hospital between 1996 and 2006,
excluding 3 stage II pts who received adjuvant CT. RFS and overall survival
(OS) were analyzed to assess the prognostic characteristics of stage II pts with
ELI (+). Of 436 pts in the database, we performed Cox regression analysis.
Covariates included age (