Background: Tailoring therapy is the target in the management of any cancer; if factors which can predict response to treatment are identified, we can individualize treatment. Locally advanced rectal cancer studies reported that tumor microenvironment and host immune response played roles in sensitivity to chemoradiotherapy (CRT) by proving that both peripheral circulating lymphocytes and tumor infiltrating lymphocytes (TILs) strongly correlated with the response rate to CRT and it impacted disease outcome. Aim of the work: We aimed to assess the predictive value of peripheral blood lymphocytes and tumor infiltrating lymphocytes by correlation with regression rate post chemo-radiotherapy in patients with rectal cancer, and to find correlation between peripheral and tissue lymphocytes. Method: Before neoadjuvant, CRT venous blood samples were obtained from 40 patients with rectal cancer, and prior to surgery. Blood cell counts in the samples were analyzed using an automated hematology analyzer and flowcytometry used to analyze lymphocyte subsets. Colonscopic biopsies were obtained before the CRT; the numbers and distributions of T cells (CD4 & CD8) were evaluated by immunostaining. Results: Pre CRT peripheral total lymphocytes, T lymphocytes, T helper, T cytotoxic lymphocytes significantly correlated with tumor regression rate ( p = 0.04, 0.05, 0.06, 0.04 respectively). The density of tissue CD4(+) and CD8(+) T cells was highly correlated with tumor regression post CRT ( p = 0.01 for both). The high expressions of tissue CD4 & CD 8 were significantly correlated with high number of pretreatment peripheral total lymphocytes, T lymphocytes, T helper, and T cytotoxic lymphocytes with significant p value for all. Conclusion: We concluded that peripheral lymphocytic count and its subsets have significant correlation to tissue CD4, CD8 and both can predict pathological response to CRT; enhancement of lymphocytes mediated immune response can help for outcome improvement.
Although the last years show much improvement in the plan of management for patients with locally advanced rectal cancer which results in improved outcomes, rectal cancer is still one of the leading causes of cancer related death [
Many researches were done to correlate the CRT sensitivity and response with multiple variables [
The immune system enhances the removal of tumor cells and work for tumor progress control [
In our study, we aim to assess the predictive value of peripheral lymphocytes, peripheral lymphocytes subsets, and tissue infiltrating lymphocytes (CD4 & CD8) by correlating to pathological response for post chemoradiotherapy in locally advanced rectal cancer and try for the first time to find correlation between peripheral lymphocyte subsets and tissue infiltrating lymphocytes (CD4 & CD8).
This prospective study included 40 patients with new diagnosed Locally Advanced Rectal Cancer (LARC) who were presented to Medical Oncology, Clinical Oncology & Nuclear Medicine and Surgery departments, Faculty of Medicine, Zagazig University in the period from December 2013 to December 2016. The study pro- tocol was approved by the Ethical Committee of Faculty of Medicine, Zagazig University.
Ø Clinical data
After baseline workup has been done in the form of colonoscopy and biopsy, pelvic MRI, chest/abdomen/pelvis CT, plus routine renal and liver functions, Carcino Embryonic Antigen (CEA) level, locally advanced rectal cancer had been confirmed.
Ø Inclusion and exclusion criteria
We included patients with Stage III rectal cancer who confirmed by pelvic MRI to have positive nodal involvement, and/or T3 and T4, adequate blood counts, hepatic, and renal function, the Eastern Cooperative Oncology Group (ECOG) performance status 0 - 2. Patients with distant metastasis, poor performance status were excluded.
Concomitant Chemo-Radiotherapy
Patients were immobilized in the prone position with a full bladder using a combination of a foam cushion and a prone head cushion. Setup marks were drawn on the patient’s skin and the cushion after laser alignment. A planning CT scan was performed using a diagnostic CT scanner. The scan extended from the L2 vertebral body to 2 cm below the perineum, and axial images were obtained at 5 mm intervals and imported to the planning system. The 3D conformal RT was employed in the treatment of all patients involved in the analysis. RT planning was accomplished using a 4-field technique box technique the clinical tumor volume (CTV) included GTV plus a 2-cm margin and nodal drainage. At risk nodes include the presacral, pelvic mesentery, and internal iliac nodes. External iliac nodes included for T4 disease. A boost field included the initial GTV plus 2 cm and the sacral hollow. All the patients were irradiated on the linear accelerator, with high energy X-rays. Patients received a total dose of 50.4 Gy, Phase 1, 45 Gy in 25 fractions, followed by a Phase 2 boost of 5.4 Gy in 3 fractions to the primary tumor, with 5 fractions per week (1.8 Gy fraction/day). Radiation therapy was given with concomitant oral 5-Fu chemotherapy capcitabine (oral flurouracil) 825 mg/m2 twice per day during radiation course with or without weekend breaks.
Surgical procedure
After an average of 6 - 8 weeks of completing CRT, patients underwent surgical resection with negative surgical margin including Total Mesorectal Resection (TMR). Surgery were either Lower Anterior Resection (LAR) in 29 patients (72.5%) or Abdominoperineal Resection (APR) in 11 patients (27.5%).
Ø Laboratory methods
Before neoadjuvant CRT, we collected peripheral venous blood samples and 4 - 6 weeks after completion of CRT from our study patients, 2 ml blood were collected in sterile EDTA vacutainer tube; the blood cell counts in the samples were analyzed by automated hematology analyzer (Sysmexxs 1000i manufactured in Japan). Flow cytometery was used to analyze lymphocyte subsets. The surface staining was done by adding 10 μl of each mAbs to 100 μl of anticoagulated blood in the same tube, incubation of tube was done in the dark, for 30 min at 4 ˚C, we did washing twice with FACS washing buffer. Lysing reagent was added to each tube, inverted once, kept for 3 minutes. Finally, 0.5 ml of Phosphate buffer saline (PBS) was added on the washed cells. Gating for the region of lymphocytes, and flow-cytometric analysis for each cell phenotype on 10,000 events was detected on the FACSCalibur flow cytometer (Becton Dickinson) using he Multiset software package (Becton Dickinson), and the CellQuest software was used for data analysis. We used a combination of isothiocyanate (FITC) and phycoerythrin (PE)-conjugated monoclonal antibody (Becton Dickinson, San Jose, CA, USA) to identify lymphocyte subsets, as follows: T lymphocyte: CD3(+)/CD19(−), B lymphocytes: CD3(−)/CD19(+), helper T lymphocytes (Th lymphocytes), CD3 (+)/CD4(+), cytotoxic T lymphocytes (Tc lymphocytes) CD3(+)/CD8(+) and for the natural killer cells: CD3(−)/CD56(+) as shown in
Ø Routine Histopathological method
Colonscopic biopsy samples which obtained from the 40 patients d before the start of CRT, fixed in 10% formalin solution, then put in paraffin, serial-step sections of the blocks were cut with 3 μm thickness, stained by routine hematoxylin & eosin stains and diagnosed in Pathology Department. Pathologic staging according to the seventh edition of the American Joint Committee on Cancer staging system (AJCC-7) classification was used [
Ø Immunohistochemical method:
The T cells numbers and distribution in biopsy samples before CRT were assessed with immunohistochemical staining with Abs against CD4 and CD8, it was performed by streptavidin biotin technique as described by Hsu and Shinto [
Ø CD4 & CD8 expressions scoring
In the densest field of CD8 & CD4 positively stained cells within epithelial compartments we counted the intraepithelial lymphocytes (IELs). TIL scoring of tumors was performed semiquantitatively by measuring the densities of CD8, CD4 cells as described by Dahlin [
Ø Pathological response evaluation
Pathological examination of surgical tissue postoperative to define who achieved complete remission, pathological N and T (ypCR was defined as the absence of any tumor cells in the operative pathology specimen defined by ypT0pN0). Regression grade evaluated depending on AJJC grading system which define 4 regre- ssion grades (G0 no residual tumor cells detected, G1 single cell or small group of cells, G2 residual cancer with desmoplastic response and G3 minimal evidence of tumor response).
SPSS 22.0 for windows (SPSS Inc., Chicago, IL, USA), MedCalc windows (MedCalc Software bvba 13, Ostend, Belgium) and Microsoft Office Excel 2010 for windows (Microsoft Cor., Redmond, WA, USA) were used. Mann Whitney U test was used for non-normally distributed variables. Percent of categorical variables were compared using Pearson’s Chi-square test or Fisher’s exact test when was appropriate. Receiver operating characteristic (ROC) curve analysis was used to identify optimal cut-off values of leukocytes subpopulations ratio with maximum sensitivity and specificity for prediction of high pathological regression rate following CRT. Univariate logistic regression analysis was done for clino-patho- logical parameters to find independent predictors of high pathological regression rate following CRT, any variables had p-value < 0.20 was entered in backward multivariate logistic regression model.
Informed consent was obtained from all participants included in the study. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Our study included 40 patients with confirmed locally advanced rectal cancer, 26 (65%) of them were males and 14 (35%) were females with age range from 33 - 70 median; 59.5 years. 33 (82.5%) cases were conventional adenocarcinoma and 7 (17.5%) cases were mucoid carcinoma. Pretreatment positive cN were seen in 75% of our patients (all details are presented in
There was a significant correlation between pretreatment clinical T & N and post treatment pathological T, pathological N (p-value 0.004 and 0.015 respectively). We did not found any significant correlation between any one of clinicopathological parameters and peripheral lymphocyte counts either pre or post CRT. Post- surgery, our patients divided into 2 groups depending on AJJC regression grade; high responders G0, 1 (Hi-R) achieved in 18 patients including 6 patients with CpCR (15%), and low responders G2, 3 (Lo-R) seen in 22 patients (55%). By using univariate analysis we found pretreatment age and clinical T were associated with good response (Hi-R) significantly (p-value 0.009 and 0.003 respectively)
For pre chemoradiotherapy counts of TLC, ANC, peripheral lymphocyte count and counts of lymphocytes subsets (T lymphocytes, Th, Tc) all showed higher median values in patients with high regression rate (Hi-R) compared to low regression (Lo-R) group as shown in
We found significant positive correlation between higher TLC, lymphocyte count, T lymphocytes, Th, Tc and regression rate for pre-CRT values, but for post CRT results we did not found any significant correlation with any of lymphocytes, or lymphocytes subsest
CD4 expression: High expression of CD4 was detected in 19 (47.5%) patients
Characteristics | All (N = 40) | |
---|---|---|
No. | (%) | |
Age (years) | 59.50 (33 - 70) | |
≤60 years | 24 | (60%) |
>60 years | 16 | (40%) |
Sex | ||
Male | 26 | (65%) |
Female | 14 | (35%) |
Pattern of gross | ||
Fungating | 26 | (65%) |
Ulcerating | 9 | (22.5%) |
Annular | 5 | (12.5%) |
Histopathological subtypes | ||
Conventional adenocarcinoma | 33 | (82.5%) |
Mucoid carcinoma | 7 | (17.5%) |
Grade | ||
Poorly differentiated | 9 | (22.5%) |
Moderately differentiated | 12 | (30%) |
Well differentiated | 19 | (47.5%) |
Distance from anal verge (cm) | 6 (2 - 12) | |
<5 cm | 14 | (35%) |
5 - 10 cm | 18 | (45%) |
>10 cm | 8 | (20%) |
Clinical T T1 T2 T3 T4 | 2 (5%) 5 (12.5%) 24 (60%) 9 (22.5%) | |
Clinical N N0 N1 N2 N3 | 10 (25%) 14 (35%) 12 (30%) 4 (10%) | |
Lymphatic invasion | ||
Absent | 29 | (72.5%) |
Present | 11 | (27.5%) |
Venous invasion | ||
Absent | 24 | (60%) |
Present | 16 | (40%) |
pCR | ||
No | 34 | (85%) |
Yes | 6 | (15%) |
Regression group | ||
3 | 8 | (20%) |
2 | 14 | (35%) |
1 | 12 | (30%) |
0 | 6 | (15%) |
Regression rate | ||
Lo-R | 22 | (55%) |
Hi-R | 18 | (45%) |
Categorical variables were expressed as number (percentage). Continuous variables were expressed as median (range). pCR (pathological Complete Remission), Lo-R (Low Regression), Hi-R (High Regression).
Univariate | Multivariate | ||||
---|---|---|---|---|---|
p-value | OR (95% CI) | p-value | |||
Gender | Male vs. Female | 0.64 | |||
Age | ≤60 years vs. >60 years | 0.04 | 11.936 | (1.241 - 114.760) | 0.03 |
Grade | Moderate vs. poor | 0.27 | |||
Distance from anal verge | >10 vs. ≤10 cm | 0.75 | |||
Clinical T | cT1-2 vs. cT3-4 | 0.04 | 11.967 | (0.666 - 214.896) | 0.09 |
Clinical N | cN0 vs. cN+ | 0.08 | |||
Pre-CRT TLC | >5200 vs. ≤5200 cell/µL | 0.09 | |||
Pre-CRT Lymphocytes | >1850 vs. ≤1850 cell/µL | 0.04 | 29.854 | (1.696 - 525.525) | 0.02 |
Pre-CRT T cells | >1310 vs. ≤1310 cell/µL | 0.09 | |||
Pre-CRT T helper | >971 vs. ≤971 cell/µL | 0.04 | |||
Pre-CRT T cytotoxic | >460 vs. ≤460 cell/µL | 0.04 | 10.861 | (0.763 - 154.628) | 0.08 |
OR: Odds Ratio; 95% CI: 95% confidence interval; p < 0.05 is significant. CRT (Chemoradiotherapy), TLC (Total Leucocyte Count).
Cut-off values | SN % (95% CI) | SP % (95% CI) | PPV % (95% CI) | NPV % (95% CI) | Accuracy (95% CI) | AUROC (95% CI) | p-value |
---|---|---|---|---|---|---|---|
Pre-CRT | |||||||
TLC >5200 cell/µL | 88.9% (65.3 - 98.6) | 54.6% (32.2 - 75.6) | 61.5% (40.1 - 80.1) | 85.7% (57.2 - 98.2) | 70% (47.1 - 86) | 0.692 (0.526 - 0.828) | 0.03 |
Lymphocytes >1850 cell/µL | 94.4% (72.7 - 99.9) | 59.1% (36.4 - 79.3) | 65.4% (44.3 - 82.8) | 92.9% (66.1 - 99.8) | 75% (52.7 - 88.6) | 0.749 (0.587 - 0.872) | 0.02 |
T cells >1310 cell/µL | 88.9% (65.3 - 98.6) | 54.6% (32.2 - 75.6) | 61.5% (40.1 - 80.1) | 85.7% (57.2 - 98.2) | 70% (47.1 - 86) | 0.764 (0.603 - 0.883) | <0.01 |
T helper >971 cell/µL | 94.4% (72.7 - 99.9) | 59.1% (36.4 - 79.3) | 65.4% (44.3 - 82.8) | 92.9% (66.1 - 99.8) | 75% (52.7 - 88.6) | 0.758 (0.596 - 0.879) | <0.01 |
T cytotoxic >460 cell/µL | 55.6% (30.8 - 78.5) | 95.5% (77.2 - 99.9) | 90.9% (56.6 - 99.8) | 72.4% (52.4 - 87.5) | 77.5% (56.3 - 90.3) | 0.750 (0.588 - 0.873) | 0.02 |
Post-CRT | |||||||
TLC >5300 cell/µL | 77.8% (52.4 - 93.6) | 77.3% (54.6 - 92.2) | 73.7% (48.8 - 90.9) | 81% (57.4 - 94.8) | 77.5% (53.6 - 92.8) | 0.745 (0.583 - 0.869) | 0.02 |
ANC >2500 cell/µL | 77.8% (52.4 - 93.6) | 68.2% (45.1 - 86.1) | 66.7% (43 - 85.4) | 78.9% (53.6 - 94.2) | 72.5% (48.4 - 89.5) | 0.702 (0.537 - 0.836) | 0.02 |
Lymphocytes ≤36.2% | 88.9% (65.3 - 98.6) | 54.6% (32.2 - 75.6) | 61.5% (40.1 - 80.1) | 85.7% (57.2 - 98.2) | 70% (47.1 - 86) | 0.703 (0.538 - 0.837) | 0.02 |
NLR >1.47 | 77.8% (52.4 - 93.6) | 68.2% (45.1 - 86.1) | 66.7% (43 - 85.4) | 78.9% (53.6 - 94.2) | 72.5% (48.4 - 89.5) | 0.756 (0.595 - 0.878) | 0.01 |
ROC curve: Receiver Operating Characteristic curve; SN: Sensitivity; SP: Specificity; PPV: Positive Predictive Value; NPV: Negative Predictive Value; AUROC: Area under Receiver Operating Characteristic Curve; 95% CI: 95% Confidence Interval; p < 0.05 is significant. CRT (Chemoradiotherapy), TLC (Total Leucocyte Count), ANC (Absolute Neutrophils Count), NK (Natural Killer), NLR (Neutrophils Lymphocytes Ratio).
Variables | All (N = 40) | Regression rate | p-value | ||||
---|---|---|---|---|---|---|---|
Lo-R (N = 22) | Hi-R (N = 18) | ||||||
Median | (Range) | Median | (Range) | Median | (Range) | ||
Pre-CRT | |||||||
TLC (cell/µL) | 7100 | (4000 - 14,100) | 5100 | (4000 - 13,000) | 8250 | (4200 - 14,100) | 0.04• |
ANC (cell/µL) | 3950 | (2000 - 9120) | 3050 | (2000 - 9120) | 4529.50 | (2200 - 9120) | 0.07• |
ANC (%) | 56.60 | (38 - 70.20) | 57.60 | (45.50 - 70.20) | 55.35 | (38 - 64.70) | 0.18* |
Lymphocyte (cell/µL) | 2357 | (980 - 4215) | 1820 | (980 - 3450) | 2920 | (1150 - 4215) | 0.04* |
Lymphocyte (%) | 33.40 | (22.90 - 43.60) | 32.90 | (22.90 - 40.50) | 33.40 | (25.90 - 43.60) | 0.12* |
T cells (cell/µL) | 1532 | (686 - 3315) | 1302.50 | (686 - 2240) | 2044 | (805 - 3315) | 0.05* |
T helper (cell/µL) | 1158 | (515 - 2453) | 910 | (515 - 1840) | 1547 | (604 - 2453) | 0.06• |
T cytotoxic (cell/µL) | 350 | (102 - 862) | 283.50 | (102 - 660) | 480 | (120 - 862) | 0.04* |
NK cells (cell/µL) | 152.50 | (68 - 423) | 137 | (68 - 400) | 167.50 | (80 - 423) | 0.18• |
B cells (cell/µL) | 562.50 | (294 - 970) | 485 | (294 - 960) | 602.50 | (345 - 970) | 0.05* |
NLR | 1.79 | (1.20 - 3.10) | 1.72 | (1.30 - 3.10) | 1.66 | (1.20 - 2.29) | 0.19* |
CEA (µg/L) | 57.50 | (3 - 390) | 65 | (3 - 390) | 49.50 | (5 - 360) | 0.97• |
Post-CRT | |||||||
TLC (cell/µL) | 5200 | (3000 - 8700) | 4250 | (3000 - 8180) | 6120.50 | (3200 - 8700) | 0.08• |
ANC (cell/µL) | 2600 | (1500 - 5120) | 2275 | (1500 - 4350) | 3275 | (1500 - 5120) | 0.03• |
ANC (%) | 52.65 | (38.40 - 66.40) | 51.30 | (42.50 - 64.50) | 55.50 | (38.40 - 66.40) | 0.99* |
Lymphocyte (cell/µL) | 1900 | (990 - 3015) | 1615 | (990 - 3015) | 2007 | (1100 - 2710) | 0.18* |
Lymphocyte (%) | 34.10 | (21.10 - 46.40) | 36.95 | (25.60 - 46.40) | 33.20 | (21.10 - 40.60) | 0.06* |
T cells (cell/µL) | 1205 | (590 - 2440) | 1132.50 | (740 - 2000) | 1410.50 | (590 - 2440) | 0.15• |
T helper (cell/µL) | 900 | (410 - 1820) | 830 | (585 - 1500) | 950 | (410 - 1820) | 0.25• |
T cytotoxic (cell/µL) | 367.50 | (130 - 760) | 277.50 | (130 - 710) | 450 | (180 - 760) | 0.07• |
NK cells (cell/µL) | 141 | (45 - 357) | 131.50 | (80 - 320) | 160 | (45 - 357) | 0.22• |
B cells (cell/µL) | 380 | (125 - 780) | 348 | (125 - 780) | 420 | (150 - 630) | 0.76* |
NLR | 1.50 | (1.01 - 2.52) | 1.35 | (1.01 - 2.52) | 1.75 | (1.23 - 2.12) | 0.06• |
CEA (µg/L) | 10 | (2 - 60) | 18 | (2 - 55) | 7.50 | (2 - 60) | 0.42• |
Continuous variables were expressed as median (range); *Independent samples Student’s t-test; •Mann Whitney U test; p < 0.05 is significant. TLC (Total Leucocyte Count), ANC (Absolute Neutrophils Count), NK (Natural Killer), NLR (Neutrophils Lymphocytes Ratio), CEA (Carcinoembyonic Antigen).
(
Characteristics | All (N = 40) | CD4 | p-value | ||||
---|---|---|---|---|---|---|---|
Low (N = 21) | High (N = 19) | ||||||
No. | (%) | No. | (%) | No. | (%) | ||
Pre-CRT laboratory findings | |||||||
TLC (cell/µL) | 7100 | (4000 - 14,100) | 5200 | (4000 - 13,000) | 8100 | (4200 - 14,100) | 0.07• |
ANC (cell/µL) | 3950 | (2000 - 9120) | 3100 | (2000 - 9120) | 4000 | (2200 - 9120) | 0.19• |
ANC (%) | 56.60 | (38 - 70.20) | 57.70 | (38 - 70.20) | 55.70 | (45.50 - 64.70) | 0.51* |
Lymphocyte (cell/µL) | 2357 | (980 - 4215) | 1840 | (980 - 3450) | 2940 | (1150 - 4215) | 0.05* |
Lymphocyte (%) | 33.40 | (22.90 - 43.60) | 32.10 | (22.90 - 38.40) | 33.90 | (25.90 - 43.60) | 0.04* |
T cells (cell/µL) | 1532 | (686 - 3315) | 1310 | (686 - 2240) | 2058 | (805 - 3315) | 0.05* |
T helper (cell/µL) | 1158 | (515 - 2453) | 920 | (515 - 1840) | 1544 | (604 - 2453) | 0.01* |
T cytotoxic (cell/µL) | 350 | (102 - 862) | 289 | (102 - 460) | 490 | (120 - 862) | 0.01* |
NK cells (cell/µL) | 152.50 | (68 - 423) | 145 | (68 - 400) | 155 | (80 - 423) | 0.28• |
B cells (cell/µL) | 562.50 | (294 - 970) | 490 | (294 - 960) | 605 | (345 - 970) | 0.10* |
Characteristics | All (N = 40) | CD8 | p-value | ||||
Low (N = 16) | High (N = 24) | ||||||
No. | (%) | No. | (%) | No. | (%) | ||
Pre-CRT laboratory findings | |||||||
TLC (cell/µL) | 7100 | (4000 - 14,100) | 6050 | (4000 - 13,000) | 7700 | (4200 - 14,100) | 0.25• |
ANC (cell/µL) | 3950 | (2000 - 9120) | 3300 | (2000 - 9120) | 4000 | (2100 - 9120) | 0.44• |
ANC (%) | 56.60 | (38 - 70.20) | 58.45 | (45.50 - 70.20) | 55.35 | (38 - 64.70) | 0.08* |
Lymphocyte (cell/µL) | 2357 | (980 - 4215) | 1820 | (980 - 3450) | 2900 | (1150 - 4215) | 0.03* |
Lymphocyte (%) | 33.40 | (22.90 - 43.60) | 30.60 | (22.90 - 38.40) | 34.55 | (25.90 - 43.60) | 0.01* |
T cells (cell/µL) | 1532 | (686 - 3315) | 1330 | (686 - 2240) | 2025 | (805 - 3315) | 0.03* |
T helper (cell/µL) | 1158 | (515 - 2453) | 910 | (515 - 1840) | 1495 | (604 - 2453) | 0.05* |
T cytotoxic (cell/µL) | 350 | (102 - 862) | 299.50 | (102 - 460) | 417 | (120 - 862) | 0.01* |
NK cells (cell/µL) | 152.50 | (68 - 423) | 152.50 | (68 - 400) | 152.50 | (80 - 423) | 0.43• |
B cells (cell/µL) | 562.50 | (294 - 970) | 446.50 | (294 - 960) | 600 | (345 - 970) | 0.09• |
Categorical variables were expressed as number (percentage). Continuous variables were expressed as median (range). *Independent samples Student’s t-test; •Mann Whitney U test; ‡Chi-square test; §Chi-square test for trend; p < 0.05 is significant.
Characteristics | All (N = 40) | CD4 | p-value | ||||
---|---|---|---|---|---|---|---|
Low (N = 21) | High (N = 19) | ||||||
No. | (%) | No. | (%) | No. | (%) | ||
ypT | |||||||
ypT0 | 6 | (15%) | 0 | (0%) | 6 | (31.6%) | 0.01§ |
ypT1 | 8 | (20%) | 2 | (9.5%) | 6 | (31.6%) | |
ypT2 | 15 | (37.5%) | 9 | (42.9%) | 6 | (31.6%) | |
ypT3 | 11 | (27.5%) | 10 | (47.6%) | 1 | (5.3%) | |
ypN |
ypN0 | 21 | (52.5%) | 9 | (42.9%) | 12 | (63.2%) | 0.19§ |
---|---|---|---|---|---|---|---|
ypN1 | 18 | (45%) | 12 | (57.1%) | 6 | (31.6%) | |
ypN2 | 1 | (2.5%) | 0 | (0%) | 1 | (5.3%) | |
Lymphatic invasion | |||||||
Absent | 29 | (72.5%) | 17 | (81%) | 12 | (63.2%) | 0.21§ |
Present | 11 | (27.5%) | 4 | (19%) | 7 | (36.8%) | |
Venous invasion | |||||||
Absent | 24 | (60%) | 13 | (61.9%) | 11 | (57.9%) | 0.79§ |
Present | 16 | (40%) | 8 | (38.1%) | 8 | (42.1%) | |
pCR | |||||||
No | 34 | (85%) | 21 | (100%) | 13 | (68.4%) | 0.07§ |
Yes | 6 | (15%) | 0 | (0%) | 6 | (31.6%) | |
Regression group | |||||||
3 | 8 | (20%) | 7 | (33.3%) | 1 | (5.3%) | <0.01§ |
2 | 14 | (35%) | 13 | (61.9%) | 1 | (5.3%) | |
1 | 12 | (30%) | 1 | (4.8%) | 11 | (57.9%) | |
0 | 6 | (15%) | 0 | (0%) | 6 | (31.6%) | |
Regression rate | |||||||
Lo-R | 22 | (55%) | 20 | (95.2%) | 2 | (10.5%) | <0.01 § |
Hi-R | 18 | (45%) | 1 | (4.8%) | 17 | (89.5%) | |
Characteristics | All (N = 40) | CD8 | p-value | ||||
Low (N = 18) | High (N = 22) | ||||||
No. | (%) | No. | (%) | No. | (%) | ||
ypT | |||||||
ypT0 | 6 | (15%) | 0 | (0%) | 6 | (27.3%) | 0.02 |
ypT1 | 8 | (20%) | 1 | (5.6%) | 7 | (31.8%) | |
ypT2 | 15 | (37.5%) | 8 | (44.4%) | 7 | (31.8%) | |
ypT3 | 11 | (27.5%) | 9 | (50%) | 2 | (9.1%) | |
ypN | |||||||
ypN0 | 21 | (52.5%) | 8 | (44.4%) | 13 | (59.1%) | 0.36 |
ypN1 | 18 | (45%) | 10 | (55.6%) | 8 | (36.4%) | |
ypN2 | 1 | (2.5%) | 0 | (0%) | 1 | (4.5%) | |
Lymphatic invasion | |||||||
Absent | 29 | (72.5%) | 14 | (77.8%) | 15 | (68.2%) | 0.72 |
Present | 11 | (27.5%) | 4 | (22.2%) | 7 | (31.8%) | |
Venous invasion | |||||||
Absent | 24 | (60%) | 10 | (55.6%) | 14 | (63.6%) | 0.60 |
Present | 16 | (40%) | 8 | (44.4%) | 8 | (36.4%) | |
pCR | |||||||
No | 34 | (85%) | 18 | (100%) | 16 | (72.7%) | 0.02 |
Yes | 6 | (15%) | 0 | (0%) | 6 | (27.3%) | |
Regression group | |||||||
3 | 8 | (20%) | 6 | (33.3%) | 2 | (9.1%) | <0.01 |
2 | 14 | (35%) | 12 | (66.7%) | 2 | (9.1%) | |
1 | 12 | (30%) | 0 | (0%) | 12 | (54.5%) | |
0 | 6 | (15%) | 0 | (0%) | 6 | (27.3%) | |
Regression rate | |||||||
Lo-R | 22 | (55%) | 18 | (100%) | 4 | (18.2%) | <0.01 |
Hi-R | 18 | (45%) | 0 | (0%) | 18 | (81.8%) |
Categorical variables were expressed as number (percentage; ‡Chi-square test for trend; p < 0.05 is significant.
Although the current multimodal treatment of locally advanced rectal cancer provided good results, we are still in need for patient-tailored treatments which expected to give greater benefit [
Kitayama et al. [
Flow cytometry analysis of peripheral lymphocyte subsets showed that; pre- CRT circulating T lymphocytes, Th lymphocytes, and Tc lymphocytes but not B lymphocytes, had positive significant correlations with the tumor regression rate and pathological response, and these are concordant with Tada et al., Demaria & Formenti, and Ma et al. [
It was previously demonstrated that the densities of CD4(+) and CD8(+) tumor-infiltrating lymphocytes (TIL) had significant association with the histolo- gical grade after CRT, also in achieving CR post CRT and the density of CD8(+) TIL was found as an independent prognostic factor [
Studies not investigate the relation between peripheral blood lymphocytes and tumor-infiltrating lymphocytes (TIL) in wide range. Milne et al. [
Preoperative neoadjuvant therapy is not like adjuvant therapy, because it provides other short term endpoints based on pathologic tumor response. It is now documented that after preoperative CRT for rectal cancer patients who achieving pathologic complete response (ypCR) have favorable long-term outcomes [
In our result, endpoints were limited to the pathologic regression but we can rely on the KROG 09-01 trial which concluded that post preoperative chemoradiotherapy in rectal cancer patients, those who gained pathological remission showed better disease outcomes. Kitayama et al. [
In conclusion, despite our study, small number of patients and short-term follow-up, we found that the pre-CRT peripheral lymphocytes count, peripheral lymphocyte subsets (T cells, Th and Tc) and tissue CD4 & CD8 were predictors of pathologic tumor regression after preoperative CRT in rectal cancer patients. Also for the first time, we proved positive significant correlation between pre-CRT peripheral lymphocyte, T lymphocytes, T helper, T cytotoxic and high tissue lymphocyte (CD4 & CD8). Immune response which is mediated by lymphocytes plays a positive role in the clinical response to CRT, and immune modulation through lymphocytes attractive mechanisms may help to get better effect for rectal cancer patients. Further studies with bigger patients’ number and longer follow-up duration are needed.
The authors indicated no sources of support in the form of grants, equipment or drugs.
The authors indicated no potential conflict of interest.
El Shorbagy, S., Elfarargy, O.M., Salem, R.A., Elnaggar, A.M., Harb, O.A., Abdelbary, A.M., Ashour, H.R. and Gertallah, L.M. (2017) Peripheral and Tissue Lymphocytes as Predictors of Patho- logical Response in Locally Advanced Rectal Cancer Post Neoadjuvant Chemoradiotherapy. Journal of Cancer Therapy, 8, 250- 267. https://doi.org/10.4236/jct.2017.83021