The Miller Lab -

The Prognostic Value of the MCPyV Serum Antibody Test

A Dual Institutional Observational Study

David M. Miller MD, PhD
MassGeneral Cancer Center
Harvard Medical School

Disclosures

No relevant disclosures

AMERK Background

Clinical assay developed by the UW Laboratory Medicine and Pathology Team
Detects circulating antibodies against the common T-Ag of MCPyV
Seropositivity near diagnosis previously reported to be associated with decreased recurrence
- Seropositive patients had HR 0.58 for recurrence¹
Used by a subset of clinicians to monitor for disease recurrence
- NPV and PPV of 99% have been reported²

Primary Aim

The primary aim of this study was to evaluate the association between initial AMERK serostatus and survival
- Four survival outcomes were evaluated
  - Recurrence
  - Event-free Survival (EFS)
  - MCC Specific Survival (MSS)
  - Overall Survival (OS)

Methods

Dual institution (MGH and BWH/DFCI) retrospective study of patients diagnosed with MCC from January 1, 2015 to September 29, 2022
Database lock was August 11, 2023
Preregistered protocol on May 14 2023 on the Center for Open Science


Characteristic	N	Overall, N = 261¹	95% CI	AMERK Status at Diagnosis	95% CI	AMERK Status at Diagnosis	95% CI
Baseline Patient Characteristics
Characteristic	N	Overall, N = 261¹	95% CI	Seronegative, N = 132¹	95% CI	Seropositive, N = 129¹	95% CI
Sex	261
Male		161 (62%)	55%, 68%	85 (64%)	56%, 72%	76 (59%)	50%, 67%
Female		100 (38%)	32%, 45%	47 (36%)	28%, 44%	53 (41%)	33%, 50%
Age	261	74 (67, 80)		76 (70, 82)	74, 78	71 (63, 78)	68, 72
Immune Suppressed	261	42 (16%)	12%, 21%	26 (20%)	13%, 28%	16 (12%)	7.5%, 20%
Primary Site	261
Head/Neck		97 (37%)	31%, 43%	69 (52%)	43%, 61%	28 (22%)	15%, 30%
Upper Extremity		54 (21%)	16%, 26%	20 (15%)	9.7%, 23%	34 (26%)	19%, 35%
Occult Primary		40 (15%)	11%, 20%	17 (13%)	7.9%, 20%	23 (18%)	12%, 26%
Lower Extremity		35 (13%)	9.6%, 18%	10 (7.6%)	3.9%, 14%	25 (19%)	13%, 27%
Trunk		24 (9.2%)	6.1%, 14%	15 (11%)	6.7%, 18%	9 (7.0%)	3.4%, 13%
Buttocks		11 (4.2%)	2.2%, 7.6%	1 (0.8%)	0.04%, 4.8%	10 (7.8%)	4.0%, 14%
Clinical Stage	261
I		108 (41%)	35%, 48%	64 (48%)	40%, 57%	44 (34%)	26%, 43%
II		49 (19%)	14%, 24%	19 (14%)	9.1%, 22%	30 (23%)	16%, 32%
III		89 (34%)	28%, 40%	42 (32%)	24%, 41%	47 (36%)	28%, 45%
IV		14 (5.4%)	3.1%, 9.0%	6 (4.5%)	1.9%, 10%	8 (6.2%)	2.9%, 12%
Not Clinically Staged		1 (0.4%)	0.02%, 2.5%	1 (0.8%)	0.04%, 4.8%	0 (0%)	0.00%, 3.6%
Pathological Stage	261
I		46 (18%)	13%, 23%	27 (20%)	14%, 29%	19 (15%)	9.3%, 22%
IIA		9 (3.4%)	1.7%, 6.7%	2 (1.5%)	0.26%, 5.9%	7 (5.4%)	2.4%, 11%
IIB		3 (1.1%)	0.30%, 3.6%	2 (1.5%)	0.26%, 5.9%	1 (0.8%)	0.04%, 4.9%
IIIA		72 (28%)	22%, 34%	32 (24%)	17%, 33%	40 (31%)	23%, 40%
IIIB		31 (12%)	8.3%, 17%	14 (11%)	6.1%, 17%	17 (13%)	8.1%, 21%
IV		6 (2.3%)	0.94%, 5.2%	3 (2.3%)	0.59%, 7.0%	3 (2.3%)	0.60%, 7.2%
Not Pathologically Staged		94 (36%)	30%, 42%	52 (39%)	31%, 48%	42 (33%)	25%, 41%
Baseline ECOG	261
0		145 (56%)	49%, 62%	66 (50%)	42%, 58%	79 (61%)	52%, 70%
1		67 (26%)	21%, 31%	36 (27%)	20%, 36%	31 (24%)	17%, 33%
2		31 (12%)	8.3%, 17%	18 (14%)	8.5%, 21%	13 (10%)	5.7%, 17%
3		12 (4.6%)	2.5%, 8.1%	7 (5.3%)	2.3%, 11%	5 (3.9%)	1.4%, 9.3%
4		1 (0.4%)	0.02%, 2.5%	1 (0.8%)	0.04%, 4.8%	0 (0%)	0.00%, 3.6%
Not Reported		5 (1.9%)	0.71%, 4.7%	4 (3.0%)	0.98%, 8.1%	1 (0.8%)	0.04%, 4.9%
¹ n (%); Median (IQR)


Characteristic	N	Overall, N = 261¹	95% CI	AMERK Status at Diagnosis	95% CI	AMERK Status at Diagnosis	95% CI
Baseline Patient Characteristics
Characteristic	N	Overall, N = 261¹	95% CI	Seronegative, N = 132¹	95% CI	Seropositive, N = 129¹	95% CI
Sex	261
Male		161 (62%)	55%, 68%	85 (64%)	56%, 72%	76 (59%)	50%, 67%
Female		100 (38%)	32%, 45%	47 (36%)	28%, 44%	53 (41%)	33%, 50%
Age	261	74 (67, 80)		76 (70, 82)	74, 78	71 (63, 78)	68, 72
Immune Suppressed	261	42 (16%)	12%, 21%	26 (20%)	13%, 28%	16 (12%)	7.5%, 20%
Primary Site	261
Head/Neck		97 (37%)	31%, 43%	69 (52%)	43%, 61%	28 (22%)	15%, 30%
Upper Extremity		54 (21%)	16%, 26%	20 (15%)	9.7%, 23%	34 (26%)	19%, 35%
Occult Primary		40 (15%)	11%, 20%	17 (13%)	7.9%, 20%	23 (18%)	12%, 26%
Lower Extremity		35 (13%)	9.6%, 18%	10 (7.6%)	3.9%, 14%	25 (19%)	13%, 27%
Trunk		24 (9.2%)	6.1%, 14%	15 (11%)	6.7%, 18%	9 (7.0%)	3.4%, 13%
Buttocks		11 (4.2%)	2.2%, 7.6%	1 (0.8%)	0.04%, 4.8%	10 (7.8%)	4.0%, 14%
Clinical Stage	261
I		108 (41%)	35%, 48%	64 (48%)	40%, 57%	44 (34%)	26%, 43%
II		49 (19%)	14%, 24%	19 (14%)	9.1%, 22%	30 (23%)	16%, 32%
III		89 (34%)	28%, 40%	42 (32%)	24%, 41%	47 (36%)	28%, 45%
IV		14 (5.4%)	3.1%, 9.0%	6 (4.5%)	1.9%, 10%	8 (6.2%)	2.9%, 12%
Not Clinically Staged		1 (0.4%)	0.02%, 2.5%	1 (0.8%)	0.04%, 4.8%	0 (0%)	0.00%, 3.6%
Pathological Stage	261
I		46 (18%)	13%, 23%	27 (20%)	14%, 29%	19 (15%)	9.3%, 22%
IIA		9 (3.4%)	1.7%, 6.7%	2 (1.5%)	0.26%, 5.9%	7 (5.4%)	2.4%, 11%
IIB		3 (1.1%)	0.30%, 3.6%	2 (1.5%)	0.26%, 5.9%	1 (0.8%)	0.04%, 4.9%
IIIA		72 (28%)	22%, 34%	32 (24%)	17%, 33%	40 (31%)	23%, 40%
IIIB		31 (12%)	8.3%, 17%	14 (11%)	6.1%, 17%	17 (13%)	8.1%, 21%
IV		6 (2.3%)	0.94%, 5.2%	3 (2.3%)	0.59%, 7.0%	3 (2.3%)	0.60%, 7.2%
Not Pathologically Staged		94 (36%)	30%, 42%	52 (39%)	31%, 48%	42 (33%)	25%, 41%
Baseline ECOG	261
0		145 (56%)	49%, 62%	66 (50%)	42%, 58%	79 (61%)	52%, 70%
1		67 (26%)	21%, 31%	36 (27%)	20%, 36%	31 (24%)	17%, 33%
2		31 (12%)	8.3%, 17%	18 (14%)	8.5%, 21%	13 (10%)	5.7%, 17%
3		12 (4.6%)	2.5%, 8.1%	7 (5.3%)	2.3%, 11%	5 (3.9%)	1.4%, 9.3%
4		1 (0.4%)	0.02%, 2.5%	1 (0.8%)	0.04%, 4.8%	0 (0%)	0.00%, 3.6%
Not Reported		5 (1.9%)	0.71%, 4.7%	4 (3.0%)	0.98%, 8.1%	1 (0.8%)	0.04%, 4.9%
¹ n (%); Median (IQR)

Association Between Serostatus & Survival

Associations between AMERK serostatus and the survival outcomes were assessed using:
- Competing risks regression model for Recurrence and MSS
- Cox proportional hazard (CoxPH) model for EFS and OS

CRR Model for Recurrence

Recurrence = β₀ + β₁I(Serostatus = Seropositive) + β₂Age +
β₃I(Sex = Male) + β₄I(Clinical Stage = IIA) +
β₅I(Clinical Stage = IIB) + β₆I(Clinical Stage = III) +
β₇I(Clinical Stage = IV) + β₈I(Baseline ECOG = 1) +
β₉I(Baseline ECOG = 2) + β₁₀I(Baseline ECOG = 3) +
β₁₁I(Baseline ECOG = Not Reported) + β₁₂I(Immune Suppressed = Yes) +
β₁₃I(Initial Treatment Summarized = Surgical Excision, Adjuvant RT) +
β₁₄I(Initial Treatment Summarized = Primary-Definitive RT) +
β₁₅I(Initial Treatment Summarized = Chemotherapy) +
β₁₆I(Initial Treatment Summarized = Immunotherapy) + ε


Complete Case Analysis	Univariable			Multivariable
Competing Risk Regression For Recurrence
Characteristic¹	N	SHR	95% CI	SHR	95% CI	p-value
Serostatus
Seronegative	119	—	—	—	—
Seropositive	120	0.49	0.31, 0.76	0.48	0.30, 0.78	0.003
Sex
Female	92	—	—	—	—
Male	147	1.75	1.07, 2.85	1.54	0.92, 2.57	0.10
Age	239	1.03	1.01, 1.05	1.01	0.98, 1.04	0.5
Clinical Stage
I	105	—	—	—	—
IIA	36	1.45	0.78, 2.71	1.94	0.99, 3.80	0.053
IIB	11	1.82	0.68, 4.89	1.82	0.65, 5.07	0.3
III	77	1.61	0.98, 2.65	1.80	1.00, 3.26	0.051
IV	10	0.68	0.17, 2.75	0.96	0.19, 4.92	>0.9
Immunocompromised
No	201	—	—	—	—
Yes	38	1.43	0.85, 2.42	1.21	0.67, 2.16	0.5
Baseline ECOG
0	141	—	—	—	—
1	62	1.85	1.13, 3.02	1.69	1.00, 2.85	0.049
2-4	36	2.44	1.39, 4.30	1.56	0.76, 3.20	0.2
Initial Treatment
Surgery Alone	30	—	—	—	—
Surgical Excision, Adjuvant Radiation	126	0.58	0.30, 1.10	0.66	0.35, 1.25	0.2
Primary-Definitive Radiation	41	1.47	0.72, 3.00	1.25	0.57, 2.75	0.6
Chemotherapy	4	1.05	0.28, 4.02	0.86	0.26, 2.78	0.8
Immunotherapy	38	0.59	0.27, 1.31	0.50	0.21, 1.17	0.11
¹ Observations: 239, Events: 83, DoF: 14, EPDF: 5.9


Complete Case Analysis	Univariable			Multivariable
Competing Risk Regression For Recurrence
Characteristic¹	N	SHR	95% CI	SHR	95% CI	p-value
Serostatus
Seronegative	119	—	—	—	—
Seropositive	120	0.49	0.31, 0.76	0.48	0.30, 0.78	0.003
Sex
Female	92	—	—	—	—
Male	147	1.75	1.07, 2.85	1.54	0.92, 2.57	0.10
Age	239	1.03	1.01, 1.05	1.01	0.98, 1.04	0.5
Clinical Stage
I	105	—	—	—	—
IIA	36	1.45	0.78, 2.71	1.94	0.99, 3.80	0.053
IIB	11	1.82	0.68, 4.89	1.82	0.65, 5.07	0.3
III	77	1.61	0.98, 2.65	1.80	1.00, 3.26	0.051
IV	10	0.68	0.17, 2.75	0.96	0.19, 4.92	>0.9
Immunocompromised
No	201	—	—	—	—
Yes	38	1.43	0.85, 2.42	1.21	0.67, 2.16	0.5
Baseline ECOG
0	141	—	—	—	—
1	62	1.85	1.13, 3.02	1.69	1.00, 2.85	0.049
2-4	36	2.44	1.39, 4.30	1.56	0.76, 3.20	0.2
Initial Treatment
Surgery Alone	30	—	—	—	—
Surgical Excision, Adjuvant Radiation	126	0.58	0.30, 1.10	0.66	0.35, 1.25	0.2
Primary-Definitive Radiation	41	1.47	0.72, 3.00	1.25	0.57, 2.75	0.6
Chemotherapy	4	1.05	0.28, 4.02	0.86	0.26, 2.78	0.8
Immunotherapy	38	0.59	0.27, 1.31	0.50	0.21, 1.17	0.11
¹ Observations: 239, Events: 83, DoF: 14, EPDF: 5.9


Complete Case Analysis	Univariable			Multivariable
Cox Regression for Event-Free Survival
Characteristic¹	N	HR	95% CI	HR	95% CI	p-value
Serostatus						0.008
Seronegative	127	—	—	—	—
Seropositive	128	0.56	0.39, 0.83	0.58	0.38, 0.87
Age	255	1.04	1.02, 1.06	1.02	1.0, 1.04	0.13
Sex						0.037
Female	98	—	—	—	—
Male	157	1.77	1.17, 2.69	1.57	1.02, 2.41
Clinical Stage						0.027
I	106	—	—	—	—
IIA	36	1.49	0.84, 2.66	2.09	1.12, 3.88
IIB	11	1.45	0.57, 3.71	1.39	0.53, 3.64
III	88	1.89	1.22, 2.93	2.16	1.30, 3.59
IV	14	1.93	0.86, 4.33	2.30	0.85, 6.25
Immune Suppressed						0.8
No	213	—	—	—	—
Yes	42	1.33	0.83, 2.12	1.06	0.65, 1.74
Baseline ECOG						0.021
0	145	—	—	—	—
1	66	1.95	1.26, 3.02	1.78	1.13, 2.81
2-4	44	3.02	1.89, 4.81	1.83	1.05, 3.19
Initial Treatment						0.038
Surgery Alone	33	—	—	—	—
Surgical Excision, Adjuvant Radiation	126	0.45	0.26, 0.78	0.48	0.26, 0.88
Primary-Definitive Radiation	46	1.36	0.76, 2.43	0.97	0.51, 1.85
Chemotherapy	4	0.71	0.16, 3.06	0.50	0.11, 2.24
Immunotherapy	45	0.81	0.43, 1.53	0.49	0.23, 1.07
Hospice	1	3.88	0.51, 29.5	3.80	0.46, 31.1
¹ Observations: 255, Events: 111, DoF: 15, EPDF: 7.4, AIC: 1126.6


Complete Case Analysis	Univariable			Multivariable
Cox Regression for Overall Survival
Characteristic¹	N	HR	95% CI	HR	95% CI	p-value
Serostatus						0.081
Seronegative	127	—	—	—	—
Seropositive	128	0.57	0.34, 0.93	0.62	0.36, 1.07
Age	255	1.05	1.02, 1.08	1.01	0.98, 1.04	0.6
Sex						0.2
Female	98	—	—	—	—
Male	157	1.91	1.10, 3.32	1.45	0.81, 2.59
Clinical Stage						0.070
I	106	—	—	—	—
IIA	36	1.84	0.85, 4.00	2.57	1.14, 5.79
IIB	11	1.51	0.45, 5.14	1.16	0.33, 4.13
III	88	2.32	1.29, 4.16	2.24	1.16, 4.34
IV	14	2.43	0.90, 6.55	1.46	0.44, 4.82
Immune Suppressed						0.5
No	213	—	—	—	—
Yes	42	1.54	0.87, 2.74	1.28	0.68, 2.38
Baseline ECOG						<0.001
0	145	—	—	—	—
1	66	2.68	1.48, 4.84	2.58	1.41, 4.71
2-4	44	6.53	3.55, 12.0	5.25	2.50, 11.0
Initial Treatment						0.009
Surgery Alone	33	—	—	—	—
Surgical Excision, Adjuvant Radiation	126	0.32	0.15, 0.68	0.37	0.16, 0.85
Primary-Definitive Radiation	46	1.49	0.73, 3.07	1.04	0.46, 2.35
Chemotherapy	4	0.49	0.06, 3.82	0.51	0.06, 4.10
Immunotherapy	45	1.23	0.59, 2.59	1.21	0.50, 2.93
Hospice	1	25.9	3.03, 222	20.2	2.11, 194
¹ Observations: 255, Events: 66, DoF: 15, EPDF: 4.4, AIC: 628.9


Complete Case	Univariable			Multivariable
Competing Risk Regression for MCC-Specific Survival
Characteristic¹	N	SHR	95% CI	SHR	95% CI	p-value
Serostatus
Seronegative	120	—	—	—	—
Seropositive	127	0.58	0.32, 1.07	0.63	0.32, 1.23	0.2
Sex
Female	94	—	—	—	—
Male	153	2.13	1.04, 4.36	1.64	0.77, 3.46	0.2
Age	247	1.03	1.0, 1.06	1.00	0.97, 1.03	0.9
Clinical Stage
I	102	—	—	—	—
IIA	35	1.37	0.42, 4.47	1.79	0.51, 6.24	0.4
IIB	11	2.00	0.44, 9.15	1.84	0.38, 8.94	0.5
III	85	3.53	1.64, 7.58	3.27	1.27, 8.40	0.014
IV	14	4.89	1.65, 14.5	2.77	0.66, 11.6	0.2
Immunocompromised
No	207	—	—	—	—
Yes	40	1.61	0.79, 3.27	1.55	0.72, 3.33	0.3
Baseline ECOG
0	142	—	—	—	—
1	63	2.43	1.24, 4.78	2.29	1.17, 4.46	0.015
2-4	42	3.29	1.51, 7.18	3.07	1.08, 8.70	0.035
Initial Treatment
Surgery Alone	31	—	—	—	—
Surgical Excision, Adjuvant Radiation	125	0.36	0.13, 0.96	0.34	0.11, 1.03	0.056
Primary-Definitive Radiation	42	1.24	0.47, 3.28	0.70	0.20, 2.46	0.6
Chemotherapy	4	0.84	0.11, 6.57	0.60	0.14, 2.65	0.5
Immunotherapy	45	1.77	0.71, 4.44	0.96	0.30, 3.13	>0.9
¹ Observations: 247, Events: 43, DoF: 14, EPDF: 3.07

Sensitivity Analyses

Signal direction persisted when sensitivity analyses were performed:
- removing subjects with “borderline” AMERK titers at baseline (75-150)
- removing subjects that received systemic therapy
- analyzing with multiple imputation

AMERK Titer Prognosic?

If being AMERK positive is “better” than AMERK negative, is being more positive better than less positive?
- i.e. Is the magnitude of the initial AMERK titer prognostic?
Subsetted on AMERK positive patients and dichotomized on the median AMERK titer (2510)
- Initial AMERK titer <2510 = “AMERK Low”
- Initial AMERK titer >=2510 = “AMERK High”


Seropositive Patients	Univariable			Multivariable
Cox Regression For Event-Free Survival
Characteristic¹	N	HR	95% CI	HR	95% CI	p-value
AMERK High/Low						>0.9
AMERK Low	63	—	—	—	—
AMERK High	65	1.79	0.98, 3.29	1.01	0.49, 2.07
Age	128	1.02	0.99, 1.05	1.03	1.00, 1.06	0.073
Sex						0.002
Female	53	—	—	—	—
Male	75	3.45	1.65, 7.20	2.96	1.40, 6.29
Clinical Stage						0.025
I	44	—	—	—	—
IIA	24	1.62	0.59, 4.48	1.27	0.44, 3.65
IIB	5	1.01	0.13, 8.07	0.71	0.09, 5.75
III	47	3.71	1.65, 8.32	3.44	1.36, 8.72
IV	8	5.25	1.71, 16.1	3.80	1.15, 12.6
¹ Observations: 128, Events: 44, DoF: 7, EPDF: 6.29


Seropositive Patients	Univariable			Multivariable
Cox Regression For Event-Free Survival
Characteristic¹	N	HR	95% CI	HR	95% CI	p-value
AMERK High/Low						>0.9
AMERK Low	63	—	—	—	—
AMERK High	65	1.79	0.98, 3.29	1.01	0.49, 2.07
Age	128	1.02	0.99, 1.05	1.03	1.00, 1.06	0.073
Sex						0.002
Female	53	—	—	—	—
Male	75	3.45	1.65, 7.20	2.96	1.40, 6.29
Clinical Stage						0.025
I	44	—	—	—	—
IIA	24	1.62	0.59, 4.48	1.27	0.44, 3.65
IIB	5	1.01	0.13, 8.07	0.71	0.09, 5.75
III	47	3.71	1.65, 8.32	3.44	1.36, 8.72
IV	8	5.25	1.71, 16.1	3.80	1.15, 12.6
¹ Observations: 128, Events: 44, DoF: 7, EPDF: 6.29

AMERK Titer and Tumor Burden

Paulson et al. previously reported that higher anti-T antigen antibody titers were present at diagnosis in seropositive patients with advanced disease compared to those with localized disease¹
We sought to evaluate the correlation between baseline titer magnitude and features associated with tumor burden
- initial stage at diagnosis
- primary cutaneous tumor size
- regional lymph node basin burden
- localized disease vs. metastatic disease

Disease Extent As an Effect Modifier

Recognizing the link between initial AMERK serostatus and disease burden, we further investigated the potential modification of the relationship between serostatus and survival by the extent of disease at diagnosis


Complete Case Analysis	Univariable				Multivariable
Cox Regression for Event-Free Survival
Characteristic¹	N	HR²	95% CI²	p-value	HR²	95% CI²	p-value
Serostatus				0.003			<0.001
Seronegative	127	—	—		—	—
Seropositive	128	0.56	0.39, 0.83		0.36	0.20, 0.66
Age	255	1.04	1.02, 1.06	<0.001	1.02	1.00, 1.04	0.12
Sex				0.005			0.055
Female	98	—	—		—	—
Male	157	1.77	1.17, 2.69		1.51	0.98, 2.32
Clinically Staged Disease Extent				0.008			0.7
Localized	153	—	—		—	—
Metastatic	102	1.66	1.14, 2.41		1.10	0.62, 1.96
Immune Suppressed				0.2			0.8
No	213	—	—		—	—
Yes	42	1.33	0.83, 2.12		1.07	0.66, 1.74
Baseline ECOG				<0.001			0.016
0	145	—	—		—	—
1	66	1.95	1.26, 3.02		1.71	1.08, 2.69
2-4	44	3.02	1.89, 4.81		2.04	1.18, 3.56
Initial Treatment				<0.001			0.086
Surgery Alone	33	—	—		—	—
Surgical Excision, Adjuvant Radiation	126	0.45	0.26, 0.78		0.57	0.31, 1.02
Primary-Definitive Radiation	46	1.36	0.76, 2.43		1.07	0.56, 2.06
Chemotherapy	4	0.71	0.16, 3.06		0.82	0.18, 3.75
Immunotherapy	45	0.81	0.43, 1.53		0.62	0.30, 1.29
Hospice	1	3.88	0.51, 29.5		4.46	0.53, 37.3
Serostatus * Disease Extent Interaction							0.007
Seropositive * Metastatic					3.05	1.34, 6.91
¹ Observations: 255, Events: 111, DoF: 13, EPDF: 8.5, AIC: 1120.3
² HR = Hazard Ratio, CI = Confidence Interval


Complete Case Analysis	Univariable				Multivariable
Cox Regression for Event-Free Survival
Characteristic¹	N	HR²	95% CI²	p-value	HR²	95% CI²	p-value
Serostatus				0.003			<0.001
Seronegative	127	—	—		—	—
Seropositive	128	0.56	0.39, 0.83		0.36	0.20, 0.66
Age	255	1.04	1.02, 1.06	<0.001	1.02	1.00, 1.04	0.12
Sex				0.005			0.055
Female	98	—	—		—	—
Male	157	1.77	1.17, 2.69		1.51	0.98, 2.32
Clinically Staged Disease Extent				0.008			0.7
Localized	153	—	—		—	—
Metastatic	102	1.66	1.14, 2.41		1.10	0.62, 1.96
Immune Suppressed				0.2			0.8
No	213	—	—		—	—
Yes	42	1.33	0.83, 2.12		1.07	0.66, 1.74
Baseline ECOG				<0.001			0.016
0	145	—	—		—	—
1	66	1.95	1.26, 3.02		1.71	1.08, 2.69
2-4	44	3.02	1.89, 4.81		2.04	1.18, 3.56
Initial Treatment				<0.001			0.086
Surgery Alone	33	—	—		—	—
Surgical Excision, Adjuvant Radiation	126	0.45	0.26, 0.78		0.57	0.31, 1.02
Primary-Definitive Radiation	46	1.36	0.76, 2.43		1.07	0.56, 2.06
Chemotherapy	4	0.71	0.16, 3.06		0.82	0.18, 3.75
Immunotherapy	45	0.81	0.43, 1.53		0.62	0.30, 1.29
Hospice	1	3.88	0.51, 29.5		4.46	0.53, 37.3
Serostatus * Disease Extent Interaction							0.007
Seropositive * Metastatic					3.05	1.34, 6.91
¹ Observations: 255, Events: 111, DoF: 13, EPDF: 8.5, AIC: 1120.3
² HR = Hazard Ratio, CI = Confidence Interval


Complete Case Analysis	Univariable				Multivariable
Cox Regression for Event-Free Survival
Characteristic¹	N	HR²	95% CI²	p-value	HR²	95% CI²	p-value
Serostatus				0.003			<0.001
Seronegative	127	—	—		—	—
Seropositive	128	0.56	0.39, 0.83		0.36	0.20, 0.66
Age	255	1.04	1.02, 1.06	<0.001	1.02	1.00, 1.04	0.12
Sex				0.005			0.055
Female	98	—	—		—	—
Male	157	1.77	1.17, 2.69		1.51	0.98, 2.32
Clinically Staged Disease Extent				0.008			0.7
Localized	153	—	—		—	—
Metastatic	102	1.66	1.14, 2.41		1.10	0.62, 1.96
Immune Suppressed				0.2			0.8
No	213	—	—		—	—
Yes	42	1.33	0.83, 2.12		1.07	0.66, 1.74
Baseline ECOG				<0.001			0.016
0	145	—	—		—	—
1	66	1.95	1.26, 3.02		1.71	1.08, 2.69
2-4	44	3.02	1.89, 4.81		2.04	1.18, 3.56
Initial Treatment				<0.001			0.086
Surgery Alone	33	—	—		—	—
Surgical Excision, Adjuvant Radiation	126	0.45	0.26, 0.78		0.57	0.31, 1.02
Primary-Definitive Radiation	46	1.36	0.76, 2.43		1.07	0.56, 2.06
Chemotherapy	4	0.71	0.16, 3.06		0.82	0.18, 3.75
Immunotherapy	45	0.81	0.43, 1.53		0.62	0.30, 1.29
Hospice	1	3.88	0.51, 29.5		4.46	0.53, 37.3
Serostatus * Disease Extent Interaction							0.007
Seropositive * Metastatic					3.05	1.34, 6.91
¹ Observations: 255, Events: 111, DoF: 13, EPDF: 8.5, AIC: 1120.3
² HR = Hazard Ratio, CI = Confidence Interval


Complete Case Analysis	Univariable				Multivariable
Cox Regression for Event-Free Survival
Characteristic¹	N	HR²	95% CI²	p-value	HR²	95% CI²	p-value
Serostatus				0.003			<0.001
Seronegative	127	—	—		—	—
Seropositive	128	0.56	0.39, 0.83		0.36	0.20, 0.66
Age	255	1.04	1.02, 1.06	<0.001	1.02	1.00, 1.04	0.12
Sex				0.005			0.055
Female	98	—	—		—	—
Male	157	1.77	1.17, 2.69		1.51	0.98, 2.32
Clinically Staged Disease Extent				0.008			0.7
Localized	153	—	—		—	—
Metastatic	102	1.66	1.14, 2.41		1.10	0.62, 1.96
Immune Suppressed				0.2			0.8
No	213	—	—		—	—
Yes	42	1.33	0.83, 2.12		1.07	0.66, 1.74
Baseline ECOG				<0.001			0.016
0	145	—	—		—	—
1	66	1.95	1.26, 3.02		1.71	1.08, 2.69
2-4	44	3.02	1.89, 4.81		2.04	1.18, 3.56
Initial Treatment				<0.001			0.086
Surgery Alone	33	—	—		—	—
Surgical Excision, Adjuvant Radiation	126	0.45	0.26, 0.78		0.57	0.31, 1.02
Primary-Definitive Radiation	46	1.36	0.76, 2.43		1.07	0.56, 2.06
Chemotherapy	4	0.71	0.16, 3.06		0.82	0.18, 3.75
Immunotherapy	45	0.81	0.43, 1.53		0.62	0.30, 1.29
Hospice	1	3.88	0.51, 29.5		4.46	0.53, 37.3
Serostatus * Disease Extent Interaction							0.007
Seropositive * Metastatic					3.05	1.34, 6.91
¹ Observations: 255, Events: 111, DoF: 13, EPDF: 8.5, AIC: 1120.3
² HR = Hazard Ratio, CI = Confidence Interval

Summary

The presence of circulating antibodies to MCPyV oncoproteins is associated with improved survival outcomes
Initial AMERK titer correlates with tumor burden
Potential effect modification exists between serostatus and disease extent

Limitations

Regional and temporally restricted retrospective study
Exploratory data analysis (strict significance testing not performed)
Low number of events

Acknowledgements

AMERK Test: Paul Nghiem, Kelly Paulson and UW Laboratory Medicine & Pathology
AMERK at BWH/DFCI: Manisha Thakuria
Data Collection: Manisha Thakuria, Ann Silk, David Miller, Kevin Emerick, Howard Kaufman
Data Abstraction: Kayla Wright, Matt Miller, Farees Saqlain, Sophia Shalhout, David Miller
Study Design: David Miller, Sophia Shalhout, Manisha Thakuria, Ann Silk, David Miller, Kevin Emerick, Howard Kaufman
Data Analysis: David Miller
Biostatistical Consultation: Harrison Reeder
Funding: Project Data Sphere
Editor and reviewers at Cancer