• Provision of informed consent prior to any study-specific procedure

• Patients with one of the following:

‣ Cohort A: Previously untreated locally advanced/metastatic HER2 -ve gastric/gastroesophageal junction/esophageal (PDL1 CPS ≥5% adenocarcinomas not amenable to curative surgery or radiotherapy who are above to begin platinum double and nivolumab.

⁃ Cohort B: Previously untreated locally advanced/metastatic Child's A hepatocellular carcinoma not amenable to curative surgery or radiotherapy who are above to begin atezolizumab and bevacizumab.

⁃ Cohort C: Previously untreated locally advanced/metastatic lung adenocarcinoma (PDL1 TPS≥50%, EGFR/ALK wildtype) not amenable to curative surgery or radiotherapy who are above to begin pembrolizumab monotherapy

• Measurable disease per RECIST 1.1 criteria

• ECOG Performance status is 0-2

• Normal organ and bone marrow function measured within 28 days before the study as defined below:

‣ Haemoglobin ≥ 8.0 g/dL and no blood transfusions in the 28 days prior to entry

⁃ Absolute neutrophil count (ANC) ≥ 1.5 x 10\^9/L

⁃ No features suggestive of MDS/AML on peripheral blood smear

⁃ White blood cells (WBC) \> 3x10\^9/L

⁃ Platelet count ≥ 100 x 10\^9/L

⁃ Total bilirubin ≤ 1.5 x institutional upper limit of normal (ULN)

⁃ AST (SGOT)/ALT (SGPT) ≤ 2.5 x institutional upper limit of normal unless liver metastases are present in which case it must be ≤ 5x ULN

⁃ Serum creatinine ≤ 1.5 x institutional upper limit of normal (ULN)

• A life expectancy ≥ 12 weeks in all patients.

• Females in childbearing age should be using adequate contraceptive measures, should not be breastfeeding and their pregnancy test prior to the start of treatment must be negative. Evidence of non-child-bearing potential is fulfilled by one of the following criteria at screening:

• The post-menopausal period defined as age ≥50 years and amenorrheic for at least 12 months following cessation of all exogenous hormonal treatments

• Women \<50 years old they have been amenorrheic for 12 months or more following cessation of exogenous hormonal treatments and with LH and FSH levels in the post-menopausal range.

⁃ Documentation of irreversible surgical sterilisation by hysterectomy, bilateral oophorectomy or bilateral salpingectomy but not a tubal ligatio

⁃ Male patients should be willing to use barrier contraception

⁃ The patient is willing to comply with the protocol during the study including undergoing treatment and scheduled visits and examinations including follow up.

⁃ At least one lesion, not previously irradiated, that can be accurately measured at baseline as ≥ 10 mm in the longest diameter (except lymph nodes which must have short axis ≥ 15 mm) with computed tomography (CT) or magnetic resonance imaging (MRI) and is considered suitable for accurate repeated measurements