Patient characteristics
The cohort included 65 MCL patients. The male to female rate was 2.61:1, and the median age was 63. Thirty-eight (58%) patients were at Ann Arbor stage Ⅰ-Ⅱ and 27 (42%) at stage Ⅲ-Ⅳ. Among these patients, 43 (66%) tumour tissue specimens were derived from lymph nodes, and others included the gastrointestinal tract, tonsil, nasopharynx, bone marrow, etc. The tumour cell morphology of 36 (55%) patients was the classical type, and 29 (45%) patients were blastoid/pleomorphic variant. Follow-up data were obtained for all 65 patients, and 51 (78%) patients died with MCL (Table1).
Table 1
Clinical and pathological features of MCL patients.
Category | | n | % |
Gender | Male | 47 | 72 |
| Female | 18 | 28 |
Age [median (range)] | | 63 (38-84) | NA |
Ann Arbor stage | Ⅰ-Ⅱ | 38 | 58 |
| Ⅲ-Ⅳ | 27 | 42 |
Tumour tissue type | Lymph node | 43 | 66 |
| Gastrointestinal tract | 9 | 14 |
| Tonsil | 5 | 8 |
| Nasopharynx | 2 | 3 |
| Bone marrow | 2 | 3 |
| Others | 4 | 6 |
Cell morphology | Classical type | 36 | 55 |
| Blastoid/Pleomorphic variant | 29 | 45 |
Survival state | Survival | 14 | 22 |
| Dead | 51 | 78 |
MCL, mantle cell lymphoma; NA, Not Applicable. |
Manual counting, computer image analysis and semiquantitative estimation of p53: correlation with survival and cell morphology
Figure 1 showed images based on manual counting (Fig. 1A) and computer image analysis (Fig. 1B) on the identical image from a representative region. The median p53 assessed by manual counting at least 1000 tumour cells was 43.1%, and the mean was 45.0% (range 0-100%). The median p53 calculated by computer image analysis of the same areas by manual counting was 53.3%, with a mean of 48.2% (range 0.1-100%). And the p53 acquired by semiquantitative estimation displayed a median of 40% and a mean of 39.4% (range 0-100%).
Manual counting, computer image analysis and semiquantitative estimation of p53 can predict OS. Each of these methods showed an AUC > 0.85 on ROC curves (P < 0.0001; Fig. 2, Table 2. The optimal p53 cut-off for predicting OS are: manual counting, cut-off value, 16.20%, sensitivity, 80.39%, specificity, 100%; computer image analysis, cut-off value, 17.66%, sensitivity, 74.51%, specificity, 100%; semiquantitative estimation, cut-off value, 5.00%, sensitivity, 76.47%, specificity, 92.86% (Table 2). As manual counting and computer image analysis are more precise than semiquantitative estimation, we used the approximate value of manual counting and computer image analysis, 20%, as the cut-off value of p53 for subsequent analysis.
Table 2
Diagnostic performance of p53 measured by different methods.
| AUC (95% CI) | P | Youden index | Optimal cut-off | Sensitivity (95% CI) | Specificity (95% CI) |
Manual counting | 0.873 (0.767 - 0.943) | <0.0001 | 0.8039 | 16.20% | 80.39% (66.9% - 90.2%) | 100% (76.8% - 100%) |
Computer image analysis | 0.853 (0.743 - 0.929) | <0.0001 | 0.7451 | 17.66% | 74.51% (60.4% - 85.7%) | 100% (76.8% - 100%) |
Semiquantitative estimation | 0.856 (0.747 - 0.931) | <0.0001 | 0.6933 | 5.00% | 76.47% (62.5% - 87.2%) | 92.86% (66.1% - 99.8%) |
AUC, area under curve; CI, confidence interval. |
To assess the prognosis of these three methods, we performed survival analysis. Kaplan-Meier survival curve analysis showed that patients with p53 < 20% have a significantly longer OS than patients with p53 ≥ 20% (P < 0.0001, Fig. 3A-C). Meanwhile, patients with blastoid MCL had shorter OS than those with classical MCL (P < 0.0001, Fig
3D). And blastoid/pleomorphic variant MCL patients had more p53 ≥ 20% as compared to classical type (P < 0.0001, Table 3).
Table 3
Correlation analysis of p53 and cell morphology.
Cell morphology | P53 by manual counting | P53 by computer image analysis | P53 by semiquantitative estimation |
< 20% | ≥ 20% | χ2 | P | < 20% | ≥ 20% | χ2 | P | < 20% | ≥ 20% | χ2 | P |
Classical type | 23 | 13 | 21.703 | < 0.0001 | 23 | 13 | 21.703 | < 0.0001 | 26 | 10 | 27.523 | < 0.0001 |
Blastoid/Pleomorphic variant | 2 | 27 | 2 | 27 | 2 | 27 |
CI, confidence interval. |
Correlation between manual counting, computer image analysis and semiquantitative estimation
There was a strong correlation between manual counting and computer image analysis of p53 in the identical areas (spearman's rho = 0.966, P < 0.0001, Fig. 4A). There was a significant correlation between manual counting and semiquantitative estimation (spearman's rho = 0.938, P < 0.0001, Fig. 4B), albeit weaker than the correlation between manual counting and computer image analysis. Moreover, we found a significant correlation between semiquantitative estimation and computer image analysis (spearman’s rho = 0.898, P < 0.001, Fig. 4C).
Bland-Altman plots comparing manual counting with computer image analysis of identical areas revealed a tendency toward a higher evaluation of p53 by computer image analysis (Fig. 4D), and comparing manual counting p53 with semiquantitative estimation revealed a tendency towards a lower evaluation of p53 by semiquantitative estimation (Fig. 4E). We also used the Bland-Altman plot to compare computer image analysis with the semiquantitative estimation of identical areas. The result revealed a tendency toward a lower evaluation of p53 by semiquantitative estimation (Fig. 4F).